Answer: Well to solve the system of equations using substitution, we'll start by solving one equation for one variable, and then substitute that expression into the other equation.
Let's solve the second equation, y = 3x - 7, for y:
y = 3x - 7 (Equation 2)
Now, we can substitute this expression for y in the first equation, 2x + y = 3:
2x + (3x - 7) = 3
Combining like terms, we have:
5x - 7 = 3
Adding 7 to both sides of the equation, we get:
5x = 10
Dividing both sides of the equation by 5, we have:
x = 2
Now that we have the value of x, we can substitute it back into one of the original equations to find the value of y. Let's use Equation 2:
y = 3x - 7
Substituting x = 2, we have:
y = 3(2) - 7
Simplifying the expression, we get:
y = 6 - 7
y = -1
Therefore, the solution to the system of equations is x = 2 and y = -1.
We can also check this solution by substituting the values of x and y back into both original equations to make sure they satisfy both equations.