7 over 10 minus 3 over 15?

Answer 1

7/10 - 3/15 = 15/30 = 1/2

Why?

You need to find the LCD (least common denominator) which is 30. Look at the work below. You must keep in mind that whatever you do to the denominator, you must do to the numerator.

7/ time 3 = 21/

10 time 3 = 30

- 3/ time 2 = 6/

15 time 2 = -30

21 - 6 = 15= 15/30 = 1/2

7/10 - 3/15 = ?

Since 3/15 can be easily reduced to 1/5, we have:

7/10 - 1/5 = ?

Then, we find the LCD of 5 and 10, which is 10, by multiplying 2 to the numerator and denominator of 1/5:

7/10 - 2/10 = 5/10 = 1/2.

Another method includes using the basic fraction and finding the LCD:

7/10 - 3/15 = ?

The LCD (LCM) is 10/5 * 15/5 * 5 = 2 * 3 * 5 = 30. Thus, multiply 3 to the numerator and denominator in 7/10, and 2 to 3/15 in the same fashion.

21/30 - 6/30 = 15/30 = 1/2.