Question

Eghh I'm so bad at Algebra >.< Help? The length of a rectangle is 9.7 cm more than 4 times the width. If the perimeter of the rectangle is 91.4 cm, what are its dimensions?

Or with this one? A rental car agency charges a flat fee of $110.00 plus $46.00 per day to rent a certain car. Another agency charges a fee of $70.00 plus $54.00 per day to rent the same car.
Using a graphing calculator, find the number of days for which the costs are the same. Round your answer to the nearest whole day.

Answer 1

l = 4w + 9.7
2l + 2w = 91.4
2(4w + 9.7) + 2w = 91.4
8w + 19.4 + 2w = 91.4
10w = 72
w = 72/10 = 7.2 cm
l = 4(7.2) + 9.7 = 38.5

Dimension = 38.5 by 7.2


Let x be the number of days for which the costs are the same, then
110 + 46x = 70 + 54x
54x - 46x = 110 - 70
8x = 40
x = 5
Therefore, it will take 5 days for the cost to be the same.