19a. Let's let # of weeks equal x and amount of savings equal s.
50+7.5x = s
19b. With this equation we can find savings in 3 weeks by plugging in 3 for x
50+7.5(3) = s
Combine like terms.
72.5 = s
19c. We first multiply 6 x 4 to give us the number of weeks.
6 x 4=24
Next we plug it in the same way as in the last problem.
50+7.5(24)=s
Combine like terms.
230=s
19d. Now we need to plug in 275 for our savings like this:
50+7.5x=275
Subtract 50 from both sides of the equation.
7.5x=225
Divide both sides by 7.5 .
x=30
HTH :)