What are the dimensions of the photograph?

Question

Mr. Mills has a photograph that is 3x - 1 1 inches wide and 4x - 2 inches tall. If the area of the pictures is 80 inches squared, what does x equal? What are the dimensions of the photograph?

Answer 1

(3x-1)(4x-2) = 80

(3x-1)(2x-1) = 40

6x^2 -5x + 1 = 40

6x^2 - 5x - 39 = 0

(6x + 13)(x - 3) = 0

6x+13 = 0 results in negative measures

x-3 = 0 ---> x = 3

THe phtoto is 3*3-1 = 9-1= 8 by (4*3-2) = 12-2 = 10

8 by 10

Answer 2

Mr. Mills has a photograph that is 3x - 1 1 inches wide and 4x - 2 inches tall. If the area of the pictures is 80 inches squared, what does x equal? What are the dimensions of the photograph?

Area = length * width

80 =(4x-2) *(3x-11)

80 =12x² -44x -6x +22

12x² -50x - 56 =0

divide by 2

4x² -25x -28 =0

(x-7)(4x+4)=0

x=7 or x=-1

x cannot negative

so x= 7

so length = 4x-2 =28-2 =46 inches

width =3x-11 =21 -11=10 inches