✔ 最佳答案
first get a common number on the bottom of 20 by multiplying the first fraction by 4/4 and the second fraction by 5/5:
(4/5)x(4/4) + (3/4)x(5/5) this gives
(4x4)/(5x4) + (3x5)/(4x5) which is
16/20 + 15/20
now just add the numbers in the tops of the fractions and leave the bottom the same
(16+15)/20
31/20 now this is just (20+11)/20 = 20/20 + 11/20 =
1 and 11/20