Answer:
10 boys
Step-by-step explanation:
if the ratio of boys to girls is 2:1, and 5 girls were there, then 1=5.
since 1=5, we can multiply it by the other number in the ratio: 2.
or you can add 5+5 because there are 2 fives
2x5=10. . therefore, 2=10 so there would be 10 boys.
hope this helps!
(A+B)(A-B) = A^2-B^2.
It's equality constant