Answer:
D.
Step-by-step explanation:
The area is the product of 2 adjacent sides:
Area = (5x - 3y)(5x - 3y) as the sides of a square are all equal.
= 5x(5x - 3y) - 3y(5x - 3y)
= 25x^2 - 15xy - 15xy + 9y^2
= 25x^2 - 30xy + 9y^2.
We know the equation of a line is y=mx+b. We know the slope (m) is -2 and all we need is the intercept (b).
Since we know one point, we can plug in 6 for x and 3 for y (along with -2 for m) in our equation and then solve for b.
3= -2*6 + b
3= -12 + b
15 = b
Since we now know the intercept we can now write our equation:
y= -2x + 15
X is 30 because
x-4x=-90
-3x=-90
x=30