If x2 - 5x + 25 = 0
Find the value of x5 - 5x4 - 3102
Answer & explanation
Correct answer: option 4
Formula → (a3 + b3) = (a + b) (a2 + b2 - ab)
x3 + 53 = (x + 5) (x2 - 5x + 25)
x3 + 53 = (x + 5) (0)
x3 = - 53
Now → x5 - 5x4 - 3102
⇒ x3 (x2 - 5x) - 3102
⇒ (-125) (-25) - 3102 (x2 - 5x +25 = 0⇒ x2 - 5x = -25)... (given)
= 3125 - 3102 = 23