Once you have a single variable isolated in one of the two equations in a system, the second step of using substitution to solve the system of equations is to a. solve for the second variable in the other equation. b. solve for the second variable in the same equation. c. substitute the expression equal to the solved variable into the other equation. d. substitute the expression equal to the solved variable into its original equation.

Step-by-step explanation:

Given that there is a system of equations in two variables. When we have a single variable isolated in one of the two equations in a system, we can use substitution method.

So we substitute this variable in terms of other variable in the second equation so that we get now an equation in one variable.  We can solve this by mathematical operations easily.

Hence correct answer is

C. substitute the expression equal to the solved variable into the other equation.

7

step-by-step explanation:

i'm assuming you need to figure out how many campers go into each tent.

i got the answer by:

24+4=28

28/4=7