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Question
If 9x+2 = 240 + 9x, then x =
Options
0.5
0.2
0.4
0.1
Solution
We have to find the value of x
Given `9 ^(x+2) = 240 +9^x`
`9^x xx 9^2 = 240 +9^x`
`9^2 = 240/9^x + 9^x/9^x`
`81= 240/9^x+ 1`
`81- 1= 240/9^x`
`80 240/9^x`
`9^x xx 80 = 240`
`9^x = 240/80`
`3^(2x )= 3`
`3^(2x )= 3^1`
By equating the exponents we get
`2x = 1`
`x= 1/2`
`x= 0.5`
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