Answer:
x = 8.94 inches
Step-by-step explanation:
Since it is already given that the area of the painting is 400 in² and the fact that area is length times width, we can make an equation and solve for x:
A=LW
400=(4x+9)(x)
400=4x^2+9x
0=4x^2+9x-400
Use the quadratic formula:
x=[-9±√(9²-4(4)(-400))]/2(4)
x=[-9±√(81+6400)]/8
x=[-9±√(6481)]/8
x = [-9+√(6481)]/8 = 8.938082281 = 8.94
x = [-9-√(6481)]/8 = -11.18808228 = -11.19
Since distance can only be positive, we will choose 8.94 as the correct solution. Therefore, x = 8.94 inches is the correct answer.
