Solve the system of equations?

Question

x + 3y = 10

3x - 6y = 15

Answer 1

x + 3y = 10
3x - 6y = 15

Solve one of the equations for a variable and then plug it in:

x = 10 -3y

3 (10-3y) -6y = 15
30 - 9y - 6y = 15
-15y = -15
y = 1

And now plug in y = 1 into your equation to get x

x + 3y = 10
x + 3(1) = 10
x + 3 = 10
x = 7

Therefore x = 7 and y =1

Answer 2

Get the idea right first!
Express x in terms of y first.
1. x=10-3y
x is now a function of y. Substitube 1 ito 3x-6y=15.
You should see that the equation is now expressed in term of only y. See the idea behind it?

Answer 3

your best bet is to solve the top equation for x and substitute into the second equation.

x = 10y - 3
3(10y-3) - 6y = 15
30y - 9 - 6y = 15

Combine like terms and solve!