The functions f:x → 2x\(^2\) + 3x -7 and g:x →5x\(^2\) + 7x – 6 are defined on the set of real numbers, R. Find the values of x for which 3f(x) = g(x).
- x = -3 or -5
- x = -3 or 5
-
x = 3 or -5
- x = 3 or 5
The correct answer is: C
Explanation
f:x → 2x\(^2\) + 3x -7 and
g:x →5x\(^2\) + 7x - 6
If 3f(x) = g(x)
3(2x\(^2\) + 3x -7) = 5x\(^2\) + 7x - 6
6x\(^2\) + 9x - 21 = 5x\(^2\) + 7x - 6
6x\(^2\) - 5x\(^2\) + 9x - 7x - 21 + 6
x\(^2\) + 2x - 15 = 0
x = 3 or -5