Question

7 7/8 - 3 1/4 equals what

Answer 1

`7 (7)/(8) -3 (1)/(4) \\ \\ (7 * 8 + 7)/(8) \\ \\ (56+7)/(8) - 3 (1)/(4) \\ \\ (63)/(8) -3 (1)/(4) \\ \\ (63)/(8) - (3 * 4 + 1)/(4) \\ \\ (63)/(8) - (12+1)/(4) \\ \\ (63)/(8) - (13)/(4) \\ \\ LCD = 8 \\ \\ (63)/(8) - (12 * 2)/(4 * 2) \\ \\ (63)/(8) - (26)/(8) \\ \\ (63 - 26)/(8) \\ \\ (37)/(8) \\ \\ \frac4{5}{8} \\ \\ Answer: \fbox {4 5/8} \ or \ \fbox {4.625}`

Answer 2

The difference of 7 and 7/8 and 3 1/4 can be restated as the difference between 63/8 and 13/4. This is just a change from mixed numbers to improper fractions.

We must now get a common denominator (the bottom part of a fraction). To get 8, we must multiply by 2 to the denominator of 13/4. Since we want this number to stay in the same value, we have to multiply the numerator by 2 as well (top part of the fraction). Therefore, we are getting the difference of 63/8 and 26/8. Doing this, we get (63-26)/8, so the answer is 37/8 = 4 5/8