how do you fnd the factors of 12 and 15.Explain

Answer 1

12 = 4(3) = 2(2)(3)

15 = 3(5)

if a number ends in 2 or any even number, you know at least one factor is 2

12/2 = 6. 6 is even so there's another factor of 2. 6/2 = 3

that gives you 2, 2 and 3 as the factors

if a number ends in 5 or 0, you know at least one factor is 5

15/5 = 3

that gives two factors, 5 and 3

it helps to know the basic multiplication tables, you need to memorize them.

here's the table for 1 through 5.

1 2 3 4 5

2 4 6 8 10

3 6 9 12 15

4 8 12 16 20

5 10 15 20 25

top row multiplied by left column gives you the other numbers in the matrix

take 4 on the top row, go down to 3 on the left column, they intersect at 12

12 has factors 3 and 4

take 2 on the top row and 2 on the left column, they intersect at 4

4 has factors 2 and 2

12 has factors 3, 2 and 2

take 5 on the top row, go down 3 on the left column and they intersect at 15

15 has factors 3 and 5