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