Answer: 10.
Explanation:
You are given the equation
(ax+b)(ax+c)=4x^2-25
Expand the Left hand side by opening the bracket.
a^2x^2 + axc + abx + bc
a^2x^2 + (axc + abx) + bc = 4x^2 + 0x - 25
From the equation above, we can see that;
a^2x^2 = 4x^2
a^2 = 4
a = √4
a = 2
Also, axc + abx = 0x
axc = abx
ax will cancel out from both sides
c = b
From the equation, bc = 25
But c = b. Substitute c for b
b^2 = 25
b = √25
b = 5 = c
b + c is therefore 5 + 5 = 10