Question

simplify (1-3n)^2 - (1+2n)(1-3n)

Answer 1

\[(a-b)(a+b) = a^2 -b^2\]\[(a-b)^2 = (a-b)^2-2ab\]

Answer 2

Use these two properties in helping you simplify your expression.

Answer 3

you could also factorise this question :).
So look at both (1 - 3n)^2 and (1+2n) (1 - 3n)
And factorise out what is common.

Answer 4

the (1-3n)?
?

Answer 5

yaaa :D So factorise out " (1 - 3n) from the equation " (1 - 3n) ^2 - (1 + 2n)(1 - 3n)"

Answer 6

so it'll become (1-3n) - (1+2n)?

Answer 7

hmm you're close but since we factorise out (1 - 3n) this means your equation actually looks like this:

(1 - 3n)^2 - (1 + 2n)(1 - 3n)

Since we factorised out (1 - 3n). We actually get:

(1 - 3n) [ (1- 3n) - (1 + 2n)]

Now you want to simplify what [ (1-3n) - (1+2n)]