17 points!
! 2 math problems only

Both answers you put into the boxes are correct.

6)We have got to solve the equations.
x - y = 16
4x + y = 9
If you add the equations y cancels out.
5x = 25
x = 5

7) 4x + y = 4
3x - 5y = -43

Here make the 'x's coefficients equal.
3( 4x + y = 4)
12x + 3y = 12 --(i)

4(3x - 5y = -43)
12x - 20y = -172 ---(ii)

Now subtracting (i) from (ii),
23y = 184
y = 8

Hope This Helps You!