Can someone please help me with math.

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Ineed with math stuff it involves graphs

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.