Marisol is painting on a piece of canvas that has an area of 180 square inches. the length of the painting is 1 1/4 times the width. what are the dimensions of the painting?

To get the area, the formula is 2l x 2w = a

so the formula will be like this: 

(x)(x+x/4)=180
where,
x is the width
x+x/4 is the height 
180 is the area

(x)(x+x/4)=180
[4(x)][4(x+x/4)]=180(4)    multiply all sides by 4 to remove the fraction
(4x)(4x+x)=720
(4x)(5x)=720  simplify 
20x^2=720   multiply 4x and 5x
20x^2=720  get the sq root of both sides
4.47x=26.83 divide by 4.47 to get the value of x
x=6

the width is 6 sq inches
the length is 7.5 sq inches
[(2)(6)][(2)(7.5)]=180
(12)(15)=180
180=180