Question

Vineet solved a system of equations by substitution. In his work, he substituted an expression for one of the variables

and solved for the value of the other. This resulted in the equation 7 = 9. What can Vineet conclude?

Answer 1

The system of equations does not have a solution.

Explanation:

For example, imagine these two equations y = x + 7 and y = x + 9

Now substitute y in the second equation with the value from the first equation:

x + 7 = x + 9

x - x + 7 = 9

0 + 7 = 9

7 = 9.

That happens because the equations represent parallel lines, which do not have a common pair of points.