Choose the equations that are not linear equations. -x - y = 2, x^2 + y = 4, x÷2 - y^3 = 1, x = 5

Step-by-step explanation:

x^2 + y = 4, is not linear because the independent variable, x, is squared.

x÷2 - y^3 = 1 is not linear because the third power of y makes this a cubic.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18