Question

Subtraction with Unequal Denominators 3/4 - 2/5=

Answer 1

Answer:

7/20

Step-by-step explanation:

We need to find a common denominator in this equation, which would be 20. By changing the fractions to this denominator you would simply get 15-8 which equals 7

Answer 2

Answer:

7/20

Step-by-step explanation:

Let's make both denominators equal to 20. To do this, you need to multiply both the numerator and denominator by the same number. Start with 3/4.

What number that when multiplied by 4 will give you 20?

That's right, 5. Let's multiply the numerator and denominator by 5 to create a new, but equivalent, fraction.

Numerator:

3 x 5 = 15

Denominator:

4 x 5 = 20

The new fraction is 15/20

Now, let's do the same thing for the fraction 2/5.

What number that when multiplied by 5 will give you 20?

You're right, it's 4! Let's multiply the numerator and denominator by 4 to create a new fraction.

Numerator:

2 x 4 = 8

Denominator:

5 x 4 = 20

The new fraction is 8/20

Finally, subtract! In order to subtract, all you have to do is subtract the numerators and keep the denominators the same.

15/20 - 8/20 = 7/20

(This is because 15 - 8 = 7)

Good job, you just subtracted fractions with different denominators! Hope this helps :)