21
x = 8, y = -1
If you mean: x+7y = 7 and 2x+y = 8 Then by substitution: x = 49/13 and y = 6/13
It is a linear equation with a single variable, y.
16
5x+8 = 10x+35x-10x = 3-8-5x = -5x = 1 and by substituting the value of x into the equations y = 13
16. Because if y=8 then the question becomes 8+8. Which equals 16.
It is 8
y=4x2+3x+8
-y + 7 = 13 -y = 6 y = -6
(1, 9)
y=6x-16 y=-2x+8
If: x+y = 8 and 2x-y = 5 Then by adding the equations together: 3x = 13 or x = 13/3 By substitution into the original equations: x = 13/3 and y = 11/3