Question

Factorise the following expressions

a) 9m^4-9m^3
b) 25x^9y^10-35x^7y^5
c) (x-1)(x-1)-3(x-1)​

Answer 1

Explanation:

A) 9m^4 - 9m^3 = 9m^3 (m - 1)

As for the number, you already took 9 out because it's common for both. As for the m, m^4 is the same as m×m×m×m. So the common between both is m×m×m = m^3.

B) 25x^9y^10 - 35x^7y^5 umm are you sure it's well written? How do you have a power in a power?

C) (x-1)(x-1)-3(x-1) = (x²-1x-1x+1) - (3x-3)

= x² - 2x + 1 - 3x + 3

= x² - 5x + 4

Answer 2

Explanation:

Rules:

Take out the GCF (greatest common factor)

a)
`9m^(4) -9m^(3)` >take out GCF, what both terms can be divided by

=9m³(m-1) >when taking out GCF, divide both terms by GCF

b)
`25x^(9)y^(10)-35x^(7)y^(5)` >GCF is
`=5x^(7)y^(5)`

`=5x^(7)y^(5)(5x^(2) y^(5)-7)`

c) (x-1)(x-1)-3(x-1)​ >GCF is (x-1)

=(x-1) [(x-1) - 3] >within the bracket you can combine like terms

=(x-1) (x-4)