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).

  • A x = -3 or -5
  • B x = -3 or 5
  • C x = 3 or -5
  • D x = 3 or 5
waec 2022furthermathematics

The correct answer is C. x = 3 or -5

f:x â†’ 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

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