Question

Factorise 3(3x-y)-(y-3x)

Answer 1

4(3x-y)

Explanation:

Given:

`\displaystyle \large{3(3x-y)-(y-3x)}`

To factor this kind of expression, first, find the common factor.

`\displaystyle \large{3(3x-y)-(-3x+y)}\\\displaystyle \large{3(3x-y)+(3x-y)}`

Notice that in the expression, we have both same (3x-y). Therefore, (3x-y) is our factor.

Let u = 3x-y

`\displaystyle \large{3u+u}\\\displaystyle \large{4u}`

Change u back to 3x-y:

`\displaystyle \large{4(3x-y)}`

Therefore, the factored expression is 4(3x-y).