Question

are the following fractions equivalent/.. 40/48 and 70/84

Answer 1

If you break them down into their lowest common denominators you can find they are equivelant.
40/48 | 70/84
divide by 2 | divide by 2
20/24 | 35/42
divide by 2 | divide by 7
10/12 | 5/6
divide by 2 |
5/6

Answer 2

With a calculator one can always convert each fraction to a decimal number.
{ 40/48 , 70/84 } -> { 0.833333, 0.833333 }