Question

If 3/4A=5/7B then A:B

Answer 1

$\frac{3}{4} a = \frac{5}{7} b$
$\frac{a}{b} = \frac{5}{7} \times \frac{4}{3}$
$\frac{a}{b} = \frac{20}{21}$

Answer 2

hey mate here is ur ans

let 3/4A=5/7B=k
=>3=4Ak=>A=3/4k
and similarly
=>5=7Bk=>B=5/7k
thus A:B=3/4k:5/7k
=(3/4)/(5/7)=(3/4)*(7/5)=21/20=21:20

hope it helps you frnd

have a good day