Question

If 4^x * 5^y = 20, 4^y * 5^x * = 20^2 Then x + y =

1
2
3
4

with explanation pls

Answer 1

Explanation:

`multiply\\4^x*5^y*4^y*5^x=20*20^2\\4^(x+y)*5^(x+y)=20^(1+2)\\(4*5)^(x+y)=20^3\\20^(x+y)=20^3\\x+y=3`