Question

-12x-5=10-7x
the answer the book gives is -3. I am not sure how they are getting it.

Answer 1

12x -5 = 10 - 7x
12x + 7x = 10 + 5
19x = 15/19
x= 19/15 = 1 full and 4/15

Answer 2

12x - 5 = 10 - 7x
12x + 7x = 10 + 5
19x = 15
19/15 = x

Answer 3

-12x-5=10-7x

try this

Answer 4

hmmm....
How is 15/19 equal 19/15?

Answer 5

The thing is is that it isn't.
Also you might want to get the asker involved instead of just providing all the works. Thanks.

Answer 6

The book is wrong if that is the right problem you have written.

Answer 7

Myininaya is right. If the book has given you the answer -3, it is wrong. Talk to your teacher about the error.

Answer 8

ill repost this seeing how it was completely ignored

-12x-5=10-7x
try this

missing a negative sign

Answer 9

you are correct. the correct equation is
-12x-5=10-7x.
The book gives and answer of -3, I still do not understand how they got that answer.

Answer 10

alright then,
the objective here is to isolate x so its alone on one side

we want to move the terms with x over to one side, in otherwords, get rid of the x term from one side

this can be accomplished if we add 12x to both sides of the equation

what happens is +12x -12x =0, so the x term cancels out on the left side

then you just combine and simplify like terms on the right

-12x-5=10-7x

-12x+12x-5=10-7x+12x

-5=10 (-7x+12x)

Answer 11

now we want to move all the constant terms over to the other side of the variable terms,

@mdgracia any ideas how you would do this?

Answer 12

subtract the -5 from each side?

Answer 13

try again

if we subtracted 5 from both sides

-5=10 -7x+12x
-5-5=10-5 -7x+12x
we would get
-10=5 -7x+12x

Answer 14

we want to remove the constant from the side with the variable

what constant is on the side of the variables?

Answer 15

so bring the 10 over to the left side.

Answer 16

yes and how would you do that?

Answer 17

add 10 to both sides?

Answer 18

close but no

we have a 10 on the right side

if we added 10 to both sides,
10+10=20

if you dont add, you ___?

Answer 19

subtract

Answer 20

ok,
-5=10 -7x+12x
-5=10+5x

i want you to subtract 10 from both sides,then write out the result

Answer 21

then I have -15=5x, divide by the 5x and get -3. right?

Answer 22

no, you're solving for x so you want isolate x so its alone without any multiples

in other words,
you want to turn 5x into x

what do you have to do?


If you divided by 5x on both sides ( you always need to do it to both sides otherwise the equation will not be balanced)

-15/5x=5x/5x

\[\frac{-3}{x}=1\]
does look right does it?

Answer 23

Yeah, I did it on both sides. Thanks for walking me through it. I hate math and I am going back and trying to fill in the gaps in my knowledge so I can get better at it.

Answer 24

the last step would just be dividing 5 from both sides of the equation

not dividing 5x

you will then get x=-3
the equation "x=-3" is your answer, not "-3"

Answer 25

That is what I wrote. It is like learning a new language for me. Thanks for the help.