derivative of 10x(x^2+7)^4
1) Let's differentiate: ddx(10x·(x2 + 7)4)
10·ddx(x·(x2 + 7)4)
For U1 = x and V2 = (x2 + 7)4, use the product/quotient rule: ddx(U1·V2) = ddx(U1)·V2 + U1·ddx(V2)
2) Let's perform the differentiation U1: ddx(x)
1
3) Let's differentiate V2: ddx((x2 + 7)4)
Apply the differentiation rule: ddx(fn) = n·ddx(f)·f(n -1) with f = x2 + 7
4·ddx(x2 + 7)·(x2 + 7)3
4·(ddx(x2) + 0)·(x2 + 7)3
4·2x·(x2 + 7)3
8x·(x2 + 7)3
4) You can evaluate the resulted derivative (U1·V2)': 1·(x2 + 7)4 + x·8x·(x2 + 7)3
(x2 + 7)4 + x2·8·(x2 + 7)3
5) Then you can resume the derivation:
10·((x2 + 7)4 + x2·8·(x2 + 7)3)
10·(x2 + 7)4 + 80x2·(x2 + 7)3
▶Derivative:   80x2·(x2 + 7)3 + 10·(x2 + 7)4