Answer:
A = 6; B = -15
Step-by-step explanation:
To have an infinite number of solutions, both equations must be the same.
4x - Ay = 15
-4x + 6y = B
The only coefficient we see in both equations is the coefficient of the x term. We have -4x and 4x. Multiply both sides of the second equation by -1.
4x - Ay = 15
4x - 6y = -B
For the equation to be equal, we need each term of one equation to be equal to the corresponding term of the other equation.
4x and 4x are equal.
-Ay must equal -6y
-Ay = -6y
-A = -6
A = 6
15 must equal -B
-B = 15
B = -15
Answer: A = 6; B = -15