How to subtract LCD - 13/20 - 2/5

13/20 - 2/5 = 1/4 ( Using LCD)

Step-by-step explanation:

Given: 13/20 - 2/5 = ? Use LCD

1) First we need find the least common multiple of the denominator (20 and 5) which is 20.

2) Since we know the least common multiple we know need to switch the two fractions up but since one of the denominator is already 20 ( 13/20) we now need to fix the other fraction (2/5).

3) We need to make it the same for both fractions so we want the same denominator as the first fraction (20) so we multiply 5 by 4 since 5 x 4 = 20 and we get 20, while also doing the same thing with the numerator. So we times 2 by 4 and we get 8.

4) Now our two fractions are now 13/20 and 8/20.

5) Our next step is to subtract the numerator, so its 13-8 which we get 5.

6) So now we have 5/20 and we want to simply to the smallest fraction so we find a number that is divisible and can make the smallest fraction which is 5.  

5/5 and 20/5 and we get 1/4.

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58