Algebraic Expressions - JSS2 Mathematics Past Questions and Answers - page 2

3(𝑥+4)=3⋅𝑥+3⋅4

=3𝑥+12

(𝑥+2)(𝑥+3)=𝑥⋅𝑥+𝑥⋅3+2⋅𝑥+2⋅3

=𝑥2+3𝑥+2𝑥+6

=𝑥2+5𝑥+6

4(𝑎−5)=4⋅𝑎−4⋅5

=4𝑎−20

6𝑥+18

Factor out the greatest common factor (GCF) which is 

6:=6(𝑥+3)

Find two numbers that multiply to 20 and add to 9 (these numbers are 4 and 5):

=(𝑥+4)(𝑥+5)

8𝑥+24

Factor out the GCF which is 8:

= 8(𝑥+3)

(𝑥+5)(𝑥+2)=𝑥⋅𝑥+𝑥⋅2+5⋅𝑥+5⋅2

=𝑥2+2𝑥+5𝑥+10

=𝑥2+7𝑥+10