Question

What are the values of a, b and c
(x^2 - 81)
x^2 - 4
36x^2 - 25
49x^2 - 1

Answer 1

1. (x^2 -81) : a = 1, b = 0, c = -81
2. (x^2 -4) : a = 1, b = 0, c = -4
3. (36x^2 -25) : a = 36, b = 0, c = -25
4. (49x^2 -1) : a = 49, b = 0, c = -1

Explanation:

You want the values of a, b and c in the quadratics (x^2 -81), (x^2 -4), (36x^2 -25), and (49x^2 -1).

Coefficients

Each of these quadratics is the difference of squares. It has the form ...

ax^2 +c

where both 'a' and '-c' are perfect squares. The coefficient 'b' is zero.

1. (x^2 -81) : a = 1, b = 0, c = -81
2. (x^2 -4) : a = 1, b = 0, c = -4
3. (36x^2 -25) : a = 36, b = 0, c = -25
4. (49x^2 -1) : a = 49, b = 0, c = -1