7/10+1/3x=25/30

Question

I got stuck at the point where I had 10/30x=4/30

Answer 1

7/10 + 1/3x = 25/30 = 5/6

7/10 + 1/3x = 5/6 multiply by 30x to remove the fractions

21x + 10 = 25x

25x-21x = 4x =-10

x = -10/4 = -5/2 = -2 1/2 or - 2.5

if you got to 10/30x = 4/30, that simplifies to 1/3x = 2/15, and 1/x =2/5, then 2x=5 or x =2.5

You must have gotten a sign wrong somewhere in your calculations, as x = negative 2.5

also it's that the problem really was supposed to read

7/10 + (1/3)x = 25/30,

multiply by 30 to get

21 + 10x = 25, subtract 21 from both sides

10x =25-21 = 4

10x = 4

divide both sides by 4

x =4/10 = 2/5 = 0.4

that solution has the + sign you have, but the inverse. You got 10/4. Reading the problem as with (1/3)x instead of 1/3x leads to 4/10, the inverse of your solution.

If you worked it as 1/3x, you got a sign wrong somewhere, but the number right

If you worked it as (1/3)x, you got the sign right but inverted something somewhere in your calculations

or when you got to 10/30x = 4/30

maybe you meant (10/30)x and not 10/(30x) ?

then it simplifies to

(1/3)x = 2/15

x = 6/15 = 2/5 = 0.4 = 4/10 which is the inverse of 10/4 = 2.5

if you meant 10/(30x) = 4/30

it simplifies to

1/3x = 2/15

1/x = 2/5

cross multiply

2x =5

x =5/2 = 2.5, the right number, but the wrong sign