Math, asked by udayj, 11 months ago

Please find 'x' in the above question

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Answers

Answered by rosangiri28pfbc5r
5
Its easy
(5)^x-3 × (3)^2x-8 = 225
(5)^x-3 × (3)^2x-8 = 5^2 × 3^2
comparing power of both side
first compare power of 5 on bothsides
x-3=2
x= 5
again compare power of 3
2x-8=2
2x=10
x= 5
hope it helps

TooFree: x cannot have 2 different values.
rosangiri28pfbc5r: i can't see the question clearly .I write 3 in place of 8 .so it happens.My idea is not wrong
TooFree: Now that you know, please correct.
rosangiri28pfbc5r: i already corrected
TooFree: :)
Answered by TooFree
10

5^{x - 3} \times 3^{2x - 8} = 225

Take out common factor 2:

5^{x - 3} \times 3^{2(x - 4)} = 225

Evaluate 3²:

5^{x - 3} \times 9^{x - 4} = 225

Apply xᵃ⁻ᵇ = xᵃ/xᵇ:

\dfrac{5^x}{5^3} \times \dfrac{9^{x}}{9^4}= 5^2 \times 3^2

Combine into single fraction:

\dfrac{5^x \times 9^x}{5^3 \times 9^4}= 5^2 \times 3^2

Apply (aˣ)(bˣ) = (ab)ˣ:

\dfrac{45^x}{5^3 \times 9^4}= 5^2 \times 3^2

Cross-multiply:

45^x= 5^2 \times 3^2 \times 5^3 \times 9^4

Evaluate 3²:

45^x= 5^2 \times 9 \times 5^3 \times 9^4

Apply xᵃ⁺ᵇ = xᵃᵇ:

45^x= 5^5 \times 9^5

Apply (aˣ)(bˣ) = (ab)ˣ:

45^x= 45^5

Evaluate x:

x = 5

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