SOLUTION: I can not figure out how to solve this problem. 3(7-2y)=9 do i divide what is in parenthesis then times by 3. i need to learn how to figure problems like this out.

Question 110583This question is from textbook
: I can not figure out how to solve this problem. 3(7-2y)=9
do i divide what is in parenthesis then times by 3. i need to learn how to figure problems like this out. This question is from textbook

Found 3 solutions by checkley71, Kalmetam, bucky:
Answer by checkley71(8403)   (Show Source): You can put this solution on YOUR website!
FIRST YOU NEED TO COMBINE THE TERMS INSIDE THE () IF POSSIBLE.
HERE YOU CANNOT.
THEN YOU MULTIPLY THE TERMS IN THE () BY 3
3*7+3*-2Y=9
21-6Y=9 NOW YOU COMBINE ALL LIKE TERMS
-6Y=9-21
-6Y=-15 NOW DIVIDE BOTH SIDES BY 6
Y=-15/-6 NOW REDUCE BY DIVIDING BY 3
Y=5/2 OR -2.5 OR -2 1/2 ARE ALL VALID ANSWERS.
Answer by Kalmetam(43)   (Show Source): You can put this solution on YOUR website!
Well you are trying to figure this out.. you do this..
--
--
3(7-2y)=9
--
There is an invisible multiplication sign in between the 3 and the first parenthese.
--
Pretend it is
--
3*(7-2y)=9
--
Now you have to find out what 2xy is.. well.. only 3x3=9, so we need to make the value in the parentheses worth 3.
--
Well multiplying comes first.. so we have to make a number with 2*2 and subtract it from 7 to =3. 7-3=4 so we need to make 2y equivalent to 4.
--
Lets try y as 2
--
3*(7-2*2)=9
3*(7-4)=9
3*3=9
--
y=2
Answer by bucky(2189)   (Show Source): You can put this solution on YOUR website!
The 3 outside the parentheses tells you to multiply each of the terms inside the parentheses by 3.
Do this first.
.
3 times 7 is 21 and 3 times -2y is -6y. So the left side is multiplied out and the equation becomes:
.
21 - 6y = 9
.
Next your goal is to get all the terms with y on one side of the equation and all the numbers
on the other side.
.
Note that if you subtract 21 from the left side the 21 will go away. But if you subtract 21
from the left side you must also subtract 21 from the right side. The first step is to subtract
21 from both sides. When you do you get:
.
21 - 6y - 21 = 9 - 21
.
On the left side 21 minus 21 is zero. On the right side 9 - 21 = -12. These two subtractions
reduce the equation to:
.
-6y = -12
.
Finally you can solve for y by dividing both sides of the equation by -6 which is the
multiplier of y. This division leads to:
.

.
On the left side the -6 in the numerator cancels the -6 in the denominator and you are left
with just y. On the right side the division of -12 in the numerator by -6 in the denominator
results in +2. So you are left with:
.
y = 2
.
This should be the answer. You can check it out by returning to the original problem,
substituting 2 for y, and making sure that the left side of the equation is equal to the
right side.
.
So start with the original equation:
.
3*(7 - 2y) = 9
.
Put 2 in for y to make this equation become:
.
3*(7 - 2*2) = 9
.
Inside the parentheses multiply the 2*2 to get 4. Put 4 in place of 2*2 and the equation
becomes:
.
3*(7 - 4) = 9
.
The number inside the parentheses is 7 - 4 which is 3. So replace 7 - 4 with 3:
.
3*(3) = 9
.
and on the left side the 3 times 3 is equal to 9 and therefore the left side is 9 and
the equation becomes:
.
9 = 9
.
Your answer of y = 2 is correct because when 2 is substituted for y in the original
problem, the left side of the equation is equal to the right side.
.
Hope this helps you to see how to work this problem.
.
RELATED QUESTIONS
I can do some of this problem, except for the very last part. Solve: 3e^4x+7=9. I get (answered by nerdybill)
I need to solve this log problem: log( 2, 32)=3x It is a change in base because it... (answered by Nate)
How do you this problem? I know the answer (it is 1), but when I do it I get 2.... (answered by pwac)
I need to know how to write this equation in order to find the answer. If I am 48 and my (answered by mananth)
I am trying to solve this problem: Divide 17/8 divided by 4/9 Supposedly the answer is... (answered by stanbon,bwpbruce)
I am not sure what kind of probelm this is or how to begin to solve it?? Can someone... (answered by solver91311)
I have a problem I need to find the mean on this problem, and I know you add them up... (answered by jsmallt9)
How do I solve the following system by graphing?? Please help 3x-6y=9 x-2y=3 Tried (answered by rchill)
The problem says for me to solve but I don't even know how to begin. I know I need an LCM (answered by stanbon)