Find the equivalent expression of the following: x3 (x2 + 5x + 7)
x5 + 5x3 + 7x2
x6 + 5x4 + 7x3
x5 + 4x4 + x4 + 8x3 – x3
x5 + 3x4 + x4 + 6x3 + x3