Question

How do you simplify `7/8 - (4/5 + 1 3/4)`?

Answer 1

`-67/40`

Explanation:

There is a mixed number in the expression. Let's make that an improper fraction:
`\color(red)(1(3/4)=4/4+3/4=7/4)`
`\therefore7/8-(4/5+\color(red)(7/4))`
Now make everything common denominator. That means LCM of 8, 5, 4 (which is 40).

Thus:
`7/8(5/5)-[4/5(8/8)+7/4(10/10)]`

`(7(5)-[4(8)+7(10)])/40=(35-(32+70))/40`

Now we can apply PEMDAS.

• Parentheses first: `32+70=102`
  `(35-102)/40`
• Now subtract:
  `-67/40`