Question

Which equation is the result of combining the equations us-

ing subtraction?
4x+6y=13
-x+6y=5

A 3x+12y = 18
B 5x=18
C 5x=8
D 3x=8

Answer 1

C. 5x=8

Explanation:

To combine the problems first take the answers (after the = ) and subtract them.

13-5=8

then take the x's and the y's and subtract the x's and y's in the other equation from them like this:

4x--x =

6y-6y=

But to do this you can also remove the x and y at the end of each number.

4--1 (when there is no number in front of an letter it means its 1)

6-6=

when you subtract a number by a negative number its almost like adding it so 4 minus negative 1 is 5 not 3.

Then 6 -6 is 0.

so you can just remove the y's because they cancel each other out.

So your final equation would be

5x=8 or answer C