please solve for x and provide steps maths
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Answer:when power is same base gets added so 4+4=8
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Answer:±1
Explanation:
i) 1/(4 + √15) = (4 - √15)/{(4 + √15)*(4 - √15)} = (4 - √15)/(16 - 15) = 4 - √15
ii) Thus the given expression is: (4 + √15)^x + {1/(4 + √15)}^x = 8
iii) Let y = (4 + √15)^x
So the given expression is: y + 1/y = 8
Rearranging, y² - 8y + 1 = 0
Solving the above using quadratics formula, y = 4 ± √15
Thus y = (4 + √15)^x = (4 + √15)
So x = 1 (equating the powers, as base is same on both sides)
Similarly considering the other value,
y = (4 + √15)^x = (4 - √15) = 1/(4 + √15) = (4 + √15)^(-1)
So again equating the powers, x = -1
Thus x = ±1
Checking the same with the given expression, both values satisfies the given equation.
So our value of x = ±1 is correct.
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