assuming that the unknown "w" is in the denominator, you can combine terms by subtracting (or adding) like terms.
3/7w - 4/9w=1/7 + 2/9
Using LCD (lowest common denominator of 63 (9 x 7)
27/63w - 28/63w = 9/63 +14/63
Multiplying both sides by 63w
27 - 28 = 9w + 14w
-1 = 23w
w = -1/23
i think this is the way that it is meant to be solved...
3/7w - 2/9 = 4/9w + 1/7
=27w - 14 / 63 = 28w + 9 / 63 ( both the 63's get cancelled since they have the same denominators. )
=27w - 28w = 9 + 14 ( you bring the 28w to the other side and change signs... that means, = 28w will become - 28w. )
= - w = 23
therefore, w = - 23 ( ANSWER )
please tell me if i am right. hope i helped!!!
Get the numbers with "w" following on the left side and the numbers not followed by a "w" on the right:
3/7w - 4/9w = 1/7 - 2/9
Next, take out the w on the left side:
w(3/7 - 4/9) = 1/7 - 2/9
Now, get the denominators to equal the same number, 63, by multiplying each number with a 7 as the denominator by (9/9) and each number with a 9 as the denominator by (7/7).
Make sure they have the least common denominator. In this case, it would be 63 (9 and 7 both go into 63)
so it would be 27/63w - 14/63 = 28/63w + 9/63
Simplify it by putting the w's on one side and the rest on the other (don't forget to change the symbols. make + a - if it is going to the other side, etc.)
27/63w - 28/63w = 14/63 + 9/63
simplify
-1/63w = 23/63
From there, multiply both sides by -64/1 (to make the w stand alone and be positive)
w= 23/63 * -63/1
w= -23