Question

(5 inmultit 3 la puterea x) -( 2 inmultit cu 3 la puterea x)=81

Answer 1

5·3la put x-2·3la put x=81
3la put x (5-2)=3 la put 4
3la put x·3=3la put 4
3la put (x+1)=3la put 4
x+1=4, x=4-1, x=3
deci
5·3la put 3-2×3la put 3=81