[tex]6x+7y=45\\9x-7y=45[/tex]
Simply eliminate y to get the value of x (Because 7y-7y=0 which is easier to get the answer and faster)
[tex]15x=90\\x=6[/tex]
15x=90 is from 6x+9x = 15x, 7y-7y = 0 and 45+45 = 90
We know the value of x, now for the value of y.
Substitute x = 6 into one of the equation, any equations but not all, just one.
So for me, I'll substitute x=6 in 6x+7y=45
[tex]6(6)+7y=45\\36+7y=45\\7y=45-36\\7y=9\\y=\frac{9}{7}[/tex]
So the answer is x = 6 and y = 9/7
