Answer:
a = ±10/9
Step-by-step explanation:

We want to use elimination to solve
y = 0 (1)
x + y = 40 (2)
Multiply (1) by -1 to eliminate y.
-y = 0 (3)
Add (2) and (3).
x + y + (-y) = 40 + 0
x = 40
Answer: Multiply by -1.
Step-by-step explanation:
2x2 is 4 4x4 is 16 16x1 is 16
Answer: 0, 4, -9
Set the equation equal to zero.
x(x - 4)(x + 9) = 0
Solve for x by setting each factor equal to zero.
The factors in the equation are x, (x - 4), and (x + 9).
x = 4
x = -9
The zeros of the function are 0, 4, and -9.