Multiply the first equation by 7 and the second equation by 2, and then add.
Explanation:
2f - 5g=-9
-7f + 3g=4
To eliminate any variable , we need to make the coefficients same with different sign and add it
the coefficient of 'f' in first equation is 2
the coefficient of 'f' in second equation is -7
We already have different sign so we make the coefficients same
To make the coefficient same , we multiply the first equation by 7 and second equation by 2
So equation becomes
14f - 35g = -63
-14f + 6g = 8
Now when we add both equations, 'f' gets cancelled
-29g = -55