Use substitution and substitute y into the other equation. One of the equations already gives you y in terms of x, so use that and substitute it into the other equation. y = 3x - 4
Plug into the other equation: -3y = -9x + 12
-3(3x-4) = -9x + 12
-9x + 12 = -9x + 12
This is an identity. So that means that any value of x makes this equation true. So B.
Okay you have 2 sum unknow lets call them X+Y
so X+Y=33, 4X=108
Get X by it self then plug it in 4X=108
X=-Y+33
4(-y+33)= 108
-4y+132=108 Then subtract the 132
-4y=-24 Y=6 then to find X subtract 33-6=27
Y=6 X=27 if you check it works out
8 1/4 is given as a positive number so you could write it as +8 1/4
The opposite of positive is negative, so you would have -(+8 1/4)
The answer is A