First, we want to find the GCF of 15 and 21, which is 3. Now we do 15 divided by 3 and 21 divided by 3, which gives us 5 and 7. To rewrite the expression, we take the GCF and put it on the outside of the parenthesis. Inside the parenthesis, we put 5 + 7. So it'll look like this:
3(5 + 7)
2 1/4 times 3 1/9
Make the fractions into decimals
So now it’s 2.25 times 3.11...
Multiply that to get 6.99 but since the 3.11... is a repeated sequence you would round it to 7, which is your answer!
Multiply the numerator and denominator by 7×2 = 14 to eliminate the denominators of those fractions:

Rationalize the denominator by multiplying both numerator and denominator by √10:

Lastly, cancel the common factor of 2 in both the numerator and denominator (which comes from 6 = 2×3 and 490 = 2×245):
