SOLUTION: I am kind of lost on these problems please help Solve find the value for the given variable Show all work and check answers showing all work 2x + 6 over 5 = x+4 over 3 3(2x+6)

Click here to see ALL problems on Expressions-with-variables

Question 210662: I am kind of lost on these problems please help
Solve find the value for the given variable Show all work and check answers showing all work
2x + 6 over 5 = x+4 over 3
3(2x+6) = 5(x+4)
6x +18 = 5x + 20 now I am confused and also don't know how to check answer

I would like to know if these are right and how to show the work to check answer
b/4 + b/3 = 7
12(b/4 + b/3) = 12(7)
12(b/4) + 12(b/3 = 84
3b + 4b = 84
7b = 84
b = 12

b/6 - b-2/8 = 4
LCD is 48
48(b/6 - b-2/8) = 48 (4)
48 (b/6 - 48 ( b-2/8) = 192
8b - 6(b-2) = 192
8b - 6b - 12 = 192
2b = 204
b = 102

Answer by vleith(2983) (Show Source):
You can put this solution on YOUR website!
Solve find the value for the given variable Show all work and check answers showing all work
2x + 6 over 5 = x+4 over 3
3(2x+6) = 5(x+4)
6x +18 = 5x + 20 now I am confused and also don't know how to check answer.
So far, so good. Collect like terms
subtract 5x from both sides and subtract 18 from both sides
simplify

2)
The work is correct. To check your answer, take your solution (12) and substitute it into the original equation. If the result is, in fact, equal, then your answer is correct. In this case
substitute in x=12

which is TRUE. so your answer is correct

b/6 - b-2/8 = 4
LCD is 48
48(b/6 - b-2/8) = 48 (4)
48 (b/6 - 48 ( b-2/8) = 192
so far, so good. You have an error in the next step.
should be remember when expanding, a negative times a negative is a positive
2b = 180
b = 90
URL to check your answer --> http://www.wolframalpha.com/input/?i=+b%2F6+-+(b-2)%2F8+%3D+4