Question

least common multiple of x^2-7x, x^2+7x

Answer 1

First we need factor them both

x² - 7x can be factored as x(x-7)
x² + 7x can be factored as x(x+7)

now if you see both factors

x ( x - 7) and x ( x+ 7)

to find the LCM we will write all the common factors for both once. The common factor for both here is 'X'. So we write that once. Then whatever factors are left we write them all.

so the LCM will be

x ( x-7) (x + 7)