Method:
Simultaneous equations
Explanation:
First we will need to get both equations to have the same subject, to do this we will multiply the bottom equation by 2.
1) 2a-3c=-6
2) a+2c=11 x2
Becomes
2) 2a+4c=22
Now we will make both equations equal to the same subject (2a)
1) 2a=3c-6
2) 2a=-4c+22
Because they are both equal to 2a, they are therefore equal to each other, so:
3c-6=-4c+22
7c=28
c=4
Now substitute c back into either equation to get a:
a+2c=11
a+2(4)=11
a=3
