To start off, Chang has already saved $45. $125 - $45 = $80. Therefore, he owes $80. $80 ÷ 7 = 11.4285714286, so he needs to work 12 full hours to pay for his trip.

Distribute 3 throught the parentheses

Move the variable to the left-hand side and change its sign

Move the constant to the right-hand side and change its sign

Collect like terms

Divide both sides of the equation by -3

The answer is letteer C. You just have to multiply 9 and pi
Solve for x.
2x + 4= 8
4x - 88 = -352
x = [?]
This is a units conversion problem: you have time and you want to convert that to money. Any units conversion problem involves multiplication by 1 in various forms. When you are given 7.5 min = 1 bottle = 500g, you know that (500 g)/(7.5 min) = 1 because the numerator and denominator are equal. (Of course, you are aware that 500 g = 0.500 kg.) The idea is to choose the forms of 1 that cause units you don't want to cancel, leaving only the units you do want.

The glass for recycling that would save enough energy to power an oven for 6 hours costs 120p.