How do you factorise 8x - 20?

Answer 1

57

Answer 2

-12

Answer 3

To factor 8x - 20, you can find the greatest common factor in both 8 and 20 and "extract" it from the expression. In this case, that common factor is 4, and the result of factoring is:

4(2x - 5)

Note that 4 times 2 is 8, and 4 times -5 is -20. Look at it this way:

8x - 20 = 4(2x) + 4(-5) = 4(2x - 5)

Notice that 2x - 5 cannot be factored any further, because 2 and 5 are both prime numbers, and their only common factor is 1.

Answer 4

-12x