Chapter 7

Elementary Algebra · 385 exercises

Problem 30

Solve. $$3 x+2-17 x-2=-48 \times 2-4$$

3 step solution

Problem 30

Barry drove the 24 miles to town and then back in 1 hour. On the return trip, he was able to average 14 miles per hour faster than he averaged on the trip to town. What was his average speed on the trip to town?

7 step solution

Problem 30

Simplify. $$ 1 x+2-1 x-3 $$

3 step solution

Problem 30

Simplify. (Assume all denominators are nonzero.) $$ 1 a b+21 a+1 b $$

3 step solution

Problem 30

Construct a mathematical model given the following. \(y\) varies directly as the square of \(x,\) where \(y=3\) when \(x=1 / 2\)

4 step solution

Problem 31

Solve. $$x-1+3=0$$

2 step solution

Problem 31

Jerry paddled his kayak upstream against a 1-mile-per-hour current for 12 miles. The return trip downstream with the 1 -mile-per-hour current took 1 hour less time. How fast can Jerry paddle the kayak in still water?

7 step solution

Problem 31

Simplify. $$ x x+1-2 x-2 $$

2 step solution

Problem 31

Simplify. (Assume all denominators are nonzero.) $$ 1 y+1 x x y $$

5 step solution

Problem 31

Construct a mathematical model given the following. \(y\) is inversely proportional to the square of \(x\), where \(y=27\) when \(x=\) \(1 / 3 .\)

5 step solution

Problem 31

State the restrictions to the domain. $$ 12 x(x+3)(2 x-1) $$

2 step solution

Problem 31

Given \(f(x)=16 \times 2-9 x+5\) and \(g(x)=x 2+3 x-104 x 2+5 x-6,\) calculate \((f \cdot g)(x)\) and state the restrictions.

3 step solution

Problem 31

Divide. (Assume all denominators are nonzero.) $$ (x-4) 230 x 4 \div x-415 x $$

5 step solution

Problem 32

Solve. $$4-y-1=0$$

3 step solution

Problem 32

It takes a light aircraft 1 hour more time to fly 360 miles against a 30 - mile-per-hour headwind than it does to fly the same distance with it. What is the speed of the aircraft in calm air?

10 step solution

Problem 32

Simplify. $$ 2 x-3 x+5-x x-3 $$

4 step solution

Problem 32

Simplify. (Assume all denominators are nonzero.) $$ 3 x 13-1 x $$

4 step solution

Problem 32

Construct a mathematical model given the following. \(y\) is inversely proportional to the square of \(x\), where \(y=9\) when \(x=\) \(2 / 3\)

4 step solution

Problem 32

State the restrictions to the domain. $$ x-3(3 x-1)(2 x+3) $$

3 step solution

Problem 32

Divide. (Assume all denominators are nonzero.) $$ 5 y 410(3 y-5) 2 \div 10 y 52(3 y-5) 3 $$

5 step solution

Problem 33

Solve. $$y-2-4=0$$

3 step solution

Problem 33

James can paint the office by himself in 7 hours. Manny paints the office in 10 hours. How long will it take them to paint the office working together?

3 step solution

Problem 33

Simplify. (Assume all denominators are nonzero.) $$ 1-4 x-21 x 21-2 x-15 x 2 $$

4 step solution

Problem 33

Construct a mathematical model given the following. \(y\) varies jointly as \(x\) and the square of \(z\), where \(y=54\) when \(x=2\) and \(z=3\)

4 step solution

Problem 33

Simplify. (Assume all denominators are nonzero.) $$ 5 x y-3 y $$

4 step solution

Problem 34

Solve. $$9 x-2-1=0$$

3 step solution

Problem 34

Barry can lay a brick driveway by himself in 12 hours. Robert does the same job in 10 hours. How long will it take them to lay the brick driveway working together?

4 step solution

Problem 34

Simplify. $$ 3 y-13 y-y+4 y-2 $$

3 step solution

Problem 34

Construct a mathematical model given the following. \(y\) varies jointly as \(x\) and the square of \(z,\) where \(y=6\) when \(x=1 / 4\) and \(z=2 / 3\)

4 step solution

Problem 34

Simplify. (Assume all denominators are nonzero.) $$ x x 2-x-6-3 x 2-x-6 $$

3 step solution

Problem 35

Solve. $$3(x-1)-1+5=0$$

4 step solution

Problem 35

Jerry can detail a car by himself in 50 minutes. Sally does the same job in 1 hour. How long will it take them to detail a car working together?

7 step solution

Problem 35

Simplify. $$ 2 x-52 x+5-2 x+52 x-5 $$

4 step solution

Problem 35

Construct a mathematical model given the following. \(y\) varies jointly as \(x\) and \(z\) and inversely as the square of \(w,\) where \(y=\) 30 when \(x=8, z=3,\) and \(w=2\)

4 step solution

Problem 36

Solve. $$5-2(3 x+1)-1=0$$

4 step solution

Problem 36

Jose can build a small shed by himself in 26 hours. Alex builds the same small shed in 2 days. How long would it take them to build the shed working together?

5 step solution

Problem 36

Simplify. $$ 22 x-1-2 x+11-2 x $$

4 step solution

Problem 36

Construct a mathematical model given the following. \(y\) varies jointly as \(x\) and \(z\) and inversely as the square of \(w,\) where \(y=5\) when \(x=1, z=3,\) and \(w=1 / 2\).

5 step solution

Problem 36

State the restrictions and then simplify. \(12 x 660 x\)

4 step solution

Problem 36

Simplify. (Assume all denominators are nonzero.) $$ 3 x-7+1-2 x x 2 $$

4 step solution

Problem 36

Divide. (Assume all denominators are nonzero.) $$ 24 a 2 b 3(a-2 b) \div 12 a b(a-2 b) 5 $$

5 step solution

Problem 37

Solve. $$3+2 x-3=2 x-3$$

3 step solution

Problem 37

Allison can complete a sales route by herself in 6 hours. Working with an associate, she completes the route in 4 hours. How long would it take her associate to complete the route by herself?

5 step solution

Problem 37

Simplify. $$ 3 x+4 x-8-28-x $$

4 step solution

Problem 37

Construct a mathematical model given the following. \(y\) varies directly as the square root of \(x\) and inversely as \(z\), where \(y=\) 12 when \(x=9\) and \(z=5\)

4 step solution

Problem 37

Simplify. (Assume all denominators are nonzero.) $$ 7 x 4 x 2-9 x+2-2 x-2 $$

4 step solution

Problem 38

James can prepare and paint a house by himself in 5 days. Working with his brother, Bryan, they can do it in 3 days. How long would it take Bryan to prepare and paint the house by himself?

5 step solution

Problem 38

Simplify. $$ 1 y-1+11-y $$

4 step solution

Problem 38

Construct a mathematical model given the following. \(y\) varies directly as the square root of \(x\) and inversely as the square of \(z,\) where \(y=15\) when \(x=25\) and \(z=2\).

4 step solution

Problem 38

State the restrictions and then simplify. $$ 20(x-3)(x-5) 6(x-3)(x+1) $$

6 step solution

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