Question

5\(^{2x-3}\)-2.5\(^2\)=5\(^2\).3

Answer 1

Ta có :

\(5^{2x-3}-2.5^2=5^2.3\\ 5^{2x-3}-2.5^2=75\)

\(5^{2x-3}-2.25=75\\ 5^{2x-3}-2=75:25\\ 5^{2x-3}-2=3\)

\(5^{2x-3}=3+2\\ 5^{2x-3}=5\)

Vì \(5^1=5\), ta có :

\(2x-3=1\)

\(2x=1+3\\ 2x=4\\ x=4:2\\ x=2\)

Vậy x =2

Answer 2

\(5^{2x-3}-2.5^2=5^2.3\\< =>5^{2x-3}-50=75\\ < =>5^{2x-3}=75+50< =>5^{2x-3}=125\\ Mà:5^3=125\\ < =>5^{2x-3}=5^3\\ < =>2x-3=3\\ < =>2x=3+3\\ < =>2x=6\\ < =>x=6:2\\ < =>x=3\)