Question

What is the answer for solving equations such as 6x-5y=15. and x=y+3

Answer 1

This is a system of equation type of problem. There are two ways of solving problems such as these: substitution and elimination.

In this problem, we are already given x.

x = y + 3

So, all we have to do is substitute y + 3 for x in the other equation.

6x - 5y = 15

Substitute

6(y + 3) - 5y = 15

Distribute

6y + 18 - 5y = 15

Combine like terms

y + 18 = 15

Subtract 18 from both sides.

y = -3

Now that we know y = -3, we can solve for the numerical value of x.

Just substitute -3 for y in either equation.

1) 6x - 5(-3) = 15

6x + 15 = 15

6x = 0

x = 0

2) x = y + 3

x = -3 + 3

x = 0

The solution for this system of equation is (0, -3).