There are 80 children. 45 of them are girls. The amount of boys is equal to:

That means there are 45 girls and 35 boys.
The ratio of boys to girls is: 
Simplify:

Your answer is 7:9
let y = x^2
4y^2 -21y + 20 = 0
solve for y
then substitute back in to get x
Answer: 3m
Step-by-step explanation:
You're multiply 3 by m. Since this isn't possible unless you have m's value, you must write the expression as 3m.
Can be achieved by dividing.
___
8 ÷ 9 = 0.8888
Therefore the answer is B