Multi step equation checks! URGENT, TEST TOMORROW!!

[PreAlgebraDummy15]

How do I check this multi step equation to make sure it's right? I'm having trouble checking them because I don't know how to set it up. Can you tell me how and show the check?? Thanks!

1. y +2-3y=-8

(I've done the work I just need the check)

y+2-3y= -8

combine y & 3y= -2y +2 = -8
-2 -2
_____________
-2y = -10
____ ____
-2 -2 = 5

2. -9-b+8b =-23
-9-7b=-23
+9 +9
______________
-7b =-14
____ _____
7 7 = -2

 

[jaggtagg7]

i am confused on some of the stuff you wrote..

but to check the solution of an equation, i would simply plug the answer i got back in for the variable,
for example, using your first one,

y+2-3y=-8
-2y+2=-8
-2y=-10
so y=5
take the answer, 5, and replace it with y in the original equation,

2(5)+2=-8
and
-10+2=-8

 

[stapel]

PreAlgebraDummy15: Please use the formatting explained in the links in the "Forum Help" pull-down menu (at the very top of the page), so that others can understand what you are trying to say. ("Karl's Notes" would probably be the quickest way to go.)

When you reply with clarification, please also include the instructions for the exercise(s) you've posted, along with specifics about what you've tried and where you're stuck.

Thank you.

Eliz.

 

[Lizzie]

Having said that. Your first one seems to be correct if your instructions are to solve for y. The other one I don't understand very well. If you repost using the LaTex format as stapel has so kindly asked you to, then we can help you out much better. Thanks!

 

[Denis]

How do I check this multi step equation to make sure it's right? I'm having trouble checking them because I don't know how to set it up. Can you tell me how and show the check?? Thanks!
1. y +2-3y=-8
(I've done the work I just need the check)
y+2-3y= -8
combine y & 3y= -2y +2 = -8
-2 -2
_____________
-2y = -10
____ ____
-2 -2 = 5
2. -9-b+8b =-23
-9-7b=-23
+9 +9
_____________
-7b =-14
____ _____
7 7 = -2

Next time, make our (and yours) life easier by going this way:
1. y + 2 - 3y = -8

2 - 2y = -8 : combine the y's
-2y = -10 : subtract 2 from each side
y = 5 : divide each side by -2

2. -9 - b + 8b = -23

7b - 9 = -23 : combine the b's
7b = 14 : add 9 to both sides
b = 2 : divide each side by 7

TRY IT!!