CUET Preparation Today
If $a^3 + b^3 = 62$ and $ a + b = 2$, then the value of ab is: |
-9 9 -6 6 |
-9 |
a + b = 2 a3 + b3 = 62 (a + b)3 = a3 + b3 + 3ab(a + b) Cubing the given equation on both the sides, (a + b)3 = 23 = a3 + b3 + 3ab(a + b) = 8 = 62 + 3ab (2) = 8 = 6ab = 8 – 62 = 6ab = -54 ab = -9 |
