Are two thirds equal to four fiths?

Answer 1

No.

Either convert to equivalent fractions with the same denominator and compare numerators:

2/3 = (2x5)/(3x5) = 10/15

4/5 = (4x3)/(5x3) = 12/15

10 ≠ 12 → the fractions are not the same

Or, convert them to decimals by dividing the numerators by the denominators:

2/3 = 2 ÷ 3 ≈ 0.667

4/5 = 4 ÷ 5 = 0.8

0.667 ≠ 0.8 → the fractions are not the same