Answer:
23/36
Explanation:
The first step you would take in solving the first part of the equation, 3/4 - 7/9, would be finding the least common denominator and rewriting the fractions. In this case, it would be 36. You would then multiply the numerator and denominator of each fraction by the number that makes its denominator equal the LCD (3 x 9, 4 x 9, 7 x 4, 9 x 4). The expression would be rewritten as 27/36 - 28/36, which leaves you with -1/36.
The last part of the equation would be to add -1/36 to 2/3, and to do this, you would have to find the LCD again- which is 36 (-1 x 1, 36 x 1, 2 x 12, 3 x 12). Now it's -1/36 + 24/36, and since the first number is negative, it's the same as subtracting one unit from a positive number. The answer you're left with is 23/36.
Hope this helps!
