Question

A rectangle has a width that is 3 less than twice the length. If the rectangle has an area of 170 square inches, what is the length of the rectangle?

Enter your answer as the correct value, with the correct unit of measurement, like this: 42 meters
Be sure to use the correct units from the context of the problem.

Answer 1

length ----- x
width ----- 2x - 3

x(2x-3) = 170
2x^2 - 3x - 170 = 0


expand, arrange as a quadratic, and solve using your favourite method.
Hint: it factors, make sure to reject the negative answer

Answer 2

im so confuse can you give me this answer so i can solve the next

Answer 3

Here's a trick my teacher thought me to break it down. Basically you're factoring polynomials, so take the 2 from 2x^2 and multiply it with 170, to give you 340.
So that leaves you with x^2 - 30 - 340= 0.
Whatever you the factors you find, set then equal to 0. Then you could find the solution.Think you can do it from there on out?

Answer 4

My apologies, x^2 - 3x - 340 = 0

Answer 5

Pardon me, I also forgot to add that whatever factors you get, to divide by 2 before you set them equal to 0. If you're still confused, let me know.

Answer 6

Språk » Hattrick

Answer 7

Or, just use the quadratic formula
2x^2 - 3x - 170 = 0
x = (3 +/- sqrt(9+1360))/4 = (3 +/- 37)/4
x = 10 or -17/2
That means the factors were
(x-10)(2x+17) = 0