a Does either of the equations have an isolated variable in it?
B
b Does either of the equations have an isolated variable in it?
A
a (10,48)
B
b (29/5,9/5)
Practice makes perfect
a In this system of equations, at least one of the variables has a coefficient of 1. Therefore, we will approach its solution with the Substitution Method.
When solving a system of equations using substitution, there are three steps.
Isolate a variable in one of the equations.
Substitute the expression for that variable into the other equation and solve.
Substitute this solution into one of the equations and solve for the value of the other variable. Since in both equations y is isolated we can choose which of them we will use for the initial substitution. Let's substitute the value of y from the first equation into the second one.
The solution, or point of intersection, to this system of equations is the point (10,48).
b Again we will find the solution of this system with the Substitution Method.
Let's recall that there are three steps when solving a system of equations using substitution.
Isolate a variable in one of the equations.
Substitute the expression for that variable into the other equation and solve.
Substitute this solution into one of the equations and solve for the value of the other variable. For this exercise, y is already isolated in one equation, so we can skip straight to solving!
