Factorising by grouping in pairs

What is the first question you ask yourself when factoring a polynomial?

• How many terms does it have?

• Is there a HCF?

• What strategy should I use?

• Why do I have to learn this?!?!?!

Factorise the following:

-9x - 27x²

• -x(9 + 27x)

• -9x(1 + 3x)

• -9(x + 3x²)

• 9x(1 - 3x)

• (x+2)(3y+4)

• (3y+2)(x+4)

• (x+3y)(x+4)

• (x+2)(x+3y)

• (5c+6)(1-k)

• (k-1)(5c-6)

• (k+1)(5c-6)

• (5c+6)(k-1)

• (a+2b)(a+c)

• (a+c)(a+b)

• (a+b)(b+c)

• (a+b)(a+2c)

What is the mathematical meaning of "Factorise"?

• To make the algebraic expression as simple as possible by grouping like-terms

• To find the value of the unknown in the algebraic equation

• To multiply the terms of the algebraic expressions

• To express the algebraic expression in their factors

• (5c+6)(1-k)

• (k-1)(5c-6)

• (k+1)(5c-6)

• (5c+6)(k-1)

• (x+2)(3y+4)

• (3y+2)(x+4)

• (x+3y)(x+4)

• (x+2)(x+3y)