Question

Use a system of equations to solve the following problem: Douglas High School has a total of 89 boys and girls who play sports. If the number of boys is 8 more than twice the number of girls, how many boys play sports at this high school?

54

27

81

62

Answer 1

89 boys and girls total
b + g = 89

boys is twice of girls PLUS 8
b = 2g + 8
---------------------
b + g = 89
b = 2g + 8

there, solve by substitution

Answer 2

To solve by substitution,
\[b + g = 89\]\[b+g-b=89-b\]\[g=89-b\]Now take\[b=2g+8\]and rewrite it substituting \((89-b)\) wherever you have \(g\):\[b=2(89-b)+8\]Expand that and solve for \(b\)