OpenStudy (chosenmatt):

2z+11=5z-7

OpenStudy (chosenmatt):

@iGreen.

OpenStudy (chosenmatt):

how would i solve this step by step?

OpenStudy (anonymous):

okay so what we can do here is move x to oneside

OpenStudy (anonymous):

sorry the z to oneside

OpenStudy (anonymous):

First we subtract 11 to both sides. $$2z + 11 = 5z - 7$$ $$2z + 11 - 11 = 5z - 7 - 11$$ See that?

OpenStudy (chosenmatt):

why 11?

OpenStudy (anonymous):

Because we have 11 there. $$2z + \color{red}{11} = 5z - 7$$ We want to get rid of that, so we SUBTRACT it to both sides, because it's being adde

OpenStudy (anonymous):

OpenStudy (chosenmatt):

ok

OpenStudy (chosenmatt):

and how do you know what to subtract 11 from?

OpenStudy (anonymous):

You subtract it to both sides of the equal sign. $$2z + 11 = 5z - 7$$ $$2z + 11 \color{red}{- 11} = 5z - 7 \color{red}{- 11}$$

OpenStudy (anonymous):

Get it?

OpenStudy (chosenmatt):

how do u subtract without knowing what z is?

OpenStudy (anonymous):

We want to get the z's on one side, and the other numbers on the other side..so we could've subtracted 2z from both sides too. $$2z + 11 = 5z - 7$$ We can get all the whole numbers on the right side, and all the z's on the left. Subtract 11 to both sides: $$2z = 5z - 7 - 11$$ Now we subtract 5z to both sides: $$2z - 5z = -7 - 11$$ Now we combine like terms.

OpenStudy (anonymous):

Get it?

OpenStudy (chosenmatt):

im still not sure

OpenStudy (chosenmatt):

@iGreen.

OpenStudy (anonymous):

OpenStudy (chosenmatt):

i got lost on the subtract 5z part

OpenStudy (chosenmatt):

@iGreen.

OpenStudy (anonymous):

We never subtracted 5z..I think you're talking about 2z? We want to get the z's on the same side, so I subtracted 2z to the other side with 5z.

OpenStudy (chosenmatt):

kay and next? @iGreen.

OpenStudy (chosenmatt):

@iGreen.

OpenStudy (anonymous):

You have to subtract: 2z - 5z and -7 - 11

OpenStudy (anonymous):

Oh yeah..we did subtract 5z to both sides..sorry.

OpenStudy (chosenmatt):

is that negative -7 and -11? @iGreen.

OpenStudy (anonymous):

That's -7z, and -7 - 11 isn't -11.

OpenStudy (chosenmatt):

wait -7z came from? im sorry lol xD

OpenStudy (anonymous):

2z - 5z = -7z

OpenStudy (chosenmatt):

OpenStudy (chosenmatt):

@igreen.

OpenStudy (anonymous):

No, we have: -7z = -18 Then we divide -7 to both sides, -18 / -7 = ?

OpenStudy (chosenmatt):

-2

OpenStudy (chosenmatt):

what did you get 18 from by the way?

OpenStudy (anonymous):

It's -18, and I got it from -7 - 11

OpenStudy (anonymous):

And -18 / -7 isn't 2..

OpenStudy (anonymous):

*-2

OpenStudy (chosenmatt):

what did you get 18 from? @igreen my last question!

OpenStudy (chosenmatt):

and 2 isnt a answer choice