Question

if 81^2x = 3^3x+ 125 find the value of 3x^2​

Answer 1

Given,

5

3x−1

÷25=125

Since, 25=5×5=5

2

And 125=5×5×5=5

3

Therefore given equation can be written as,

5

3x−1

÷(5)

2

=(5)

3

⇒(5)

3x−1−2

=(5)

3

[∵a

m

÷a

n

=(a)

m−n

]

⇒(5)

3x−3

=(5)

3

On comparing both sides, we get

⇒3x−3=3

⇒3x=6

⇒x=2

Hence, the value of x=2