#1**+3 **

(2x -1)*(x - 2) = 20, solve for x

(x - 2) (2 x - 1) = 20

Expand out terms of the left hand side:

2 x^2 - 5 x + 2 = 20

Divide both sides by 2:

x^2 - (5 x)/2 + 1 = 10

Subtract 1 from both sides:

x^2 - (5 x)/2 = 9

Add 25/16 to both sides:

x^2 - (5 x)/2 + 25/16 = 169/16

Write the left hand side as a square:

(x - 5/4)^2 = 169/16

Take the square root of both sides:

x - 5/4 = 13/4 or x - 5/4 = -13/4

Add 5/4 to both sides:

x = 9/2 or x - 5/4 = -13/4

Add 5/4 to both sides:

**x = 9/2 * 2 - 1 = 8 units. ** or x = -2(Discard this one)

Guest Apr 24, 2018

#2**+3 **

We have

Area = L * W

20 = (2x - 1) (x - 2) simplify

20 = 2x^2 - x - 4x + 2 subtract 20 from both sides and we have

2x^2 - 5x - 18 = 0 factor

(2x - 9) ( x + 2) = 0

Only the first factor set to 0 will yield a positive result for x

2x - 9 = 0

2x = 9

x = 9/2

So....the length is 2(9/2) - 1 = 9 - 1 = 8

CPhill
Apr 24, 2018