A total of 300 children and adults attended a school play. There were 21 times as many children in attendance as there

were adults.

This situation is modeled by the given system of equations, where a represents the number of adults and c represents the

number of children.

c = 21a

a + c = 330

How many children attended the play?

were adults.

This situation is modeled by the given system of equations, where a represents the number of adults and c represents the

number of children.

c = 21a

a + c = 330

How many children attended the play?

**Use the given system of equations to solve for c, the number of children attending.**

**c = 21a**

a + c = 330

a + c = 330

a + 21a = 330 {substituted 21a, in for c, into second equation}

22a = 330 {combined like terms}

a = 15 {divided each side by 22}

15 adults attended

c = 21a {first original equation}

c = 21(15) {substituted 15, in for a, into first equation}

c = 315 {multiplied}

**315 children attended**

**Ask Algebra House**