Practicing Success
If $x-y=4$ and $x^3-y^3=316, y>0$ then the value of $x^4-y^4$ is: |
2500 2320 2401 2482 |
2320 |
Given, x - y = 4 x3 – y3 = 316 We know, x3 – y3 = (x - y)[(x - y)2 + 3xy] x3 – y3 = (x - y)[(x - y)2 + 3xy] = 316 = 4[(x - y)2 + 3xy] = 79 = [16 + 3xy] = 63 = 3xy = xy = 21 So, x = 7 y = 3 x4 - y4 = 74 - 34 = 2320 |