A tip: Just solve & solve it, you will end up having solution.
At first,
- 4e² + 24e = 9f² - 36f
- 4e(e + 6) = 9f(f - 4)
On comparing, we can say that,
- e + 6 = f - 4
- e = f - 4 - 6
- e = f - 10 - - - - - - equation(i)
Put e = f - 10 in 4e = 9f
- 4(f - 10) = 9f
- 4f - 40 = 9f
- - 40 = 9f - 4f
- -40/5 = f
- -8 = f
Put f = -8 in equation(i) to find the value of e;
- e = f - 10
- e = -8 - 10
- e = -18
And finally we have got f = -8 & e = -18, now let procede futher;
- 5/4(2e-3f)²
- 5/4 × {2(-18) - 3(-8)}²
- 5/4 × ( -36 + 24)²
- 5/4 × (-12)²
- 5/4 × 144
- 5 × 36
- 180
Thus, our final answer is 180.