What is Dydx of x(x-10)?
Assuming y = x(x - 10)
Either use the product rule:
u = x
v = (x - 10)
→ y = x(x - 10) = uv
d/dx (uv) = v du/dx + u dv/dx
→ dy/dx = d/dx x(x - 10)
= (x - 10)(d/dx x) + (x)(d/dx (x - 10))
= (x - 10)(1) + (x)(1)
= x - 10 + x
= 2x - 10
or expand the brackets and differentiate
dy/dx = d/dx x(x - 10)
= d/dx x² - 10x
= 2x - 10