(2x+4)(x-2)
please help

2x squared - 8

Step-by-step explanation:

For this kind of equation, we use the distributive property

So in the image below I used a box method (that's how I learned it in school)

So since -4x and 4x cancel each other out, or amount to 0, we don't put anything for those. So the equation left is 2x squared - 8

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