Verified answer

1. 3(x +7)

2. 6(x +3)

You look for the greatest common factor.

okay, well to factorise you take out a common factor in the expression.

For example, in the first one, you can take out 3 because 3 is a factor of both 3 and 21. However you can't take out x because it is only on one side. so outside the brackets you have just 3.

the answer is 3(x+7) because in the brackets you have to see what you need to multiply 3 by to get 3x. you have to multiply 3 by x to get 3x. then you have to see what you need to multiply 3 by to get 21. 3 multiplied by +7 is 21. hence 3(x+7)

and the second one would be 6(x+3)

putting brackets in ah easy.........

FIRST look at each equation. in equation 1 we can see that there is a 3X then we see a 21. first see if there any COMMON factors such as letters in each case. since 21 doesn't have an 'x' attached to it, it cannot be a common factor in both numbers. next we look at common multiples in each case. YES we have 3 and 21 - 3 goes into 3 once, and into 21 7 times......so this can be factorised! REMEMBER ONLY COMMON FACTORS ARE PUT OUTSIDE THE BRACKETS so when they are expanded again, you come up with the original answer.....

(a) becomes....3(x+7) -

PROOF - expanded out = 3X+21

(b) becomes.......6(x +3)

PROOF- expanded out = 6X+18

hope this helps

You look for something that the items in the expression have in common. Sometimes its numbers , sometimes its letters, sometimes it is both.

Then, you use brackets to separate and/or gather together.

1] 3 will divide into both

Gives

3 (x + 7)............In this case the two factors are 3 and (x + 7)

2] 6 will divide into both

Gives

6( 2x + 3)..........In this case the two factors are 6 and (2x + 3)

If you multiplied the factors together you would get back to the expressions you started with

factorising means putting brackets in

look for common factors in each term..largest factors that go into both goes outside the bracket

3(x+7)

6(x+3)

multiply those out and you would get what you started with...

3x+21=3(x+7)

6x+18=6(x+3)

3(x+7) and 6(x+3) are the solutions.