Find x if 2^2x-2^(x+3)+2⁴=0.
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Answered by
13
2^2x - 2^2 × 2^3 +16 = 0
Put t =2^x
t^2- 8t + 16=0
(t-4)(t-4)=0
2^x=2^2
x=2
Put t =2^x
t^2- 8t + 16=0
(t-4)(t-4)=0
2^x=2^2
x=2
Anonymous:
Its 2^2x in 1st step
Answered by
12
2^2x can be written as (2^x)²
2^(x+3)=(2^x)(2³)
now substitute these values in the question ,we get
2^x(2^x-2³)=-2⁴
2^x(2^x-8)=-16
let 2^x be y
y(y-8)=-16
y²-8y+16=0
(y-4)²=0
y=4
but y =2^x
so 2^x=4=2²
x=2
I hope this will help u ;)
2^(x+3)=(2^x)(2³)
now substitute these values in the question ,we get
2^x(2^x-2³)=-2⁴
2^x(2^x-8)=-16
let 2^x be y
y(y-8)=-16
y²-8y+16=0
(y-4)²=0
y=4
but y =2^x
so 2^x=4=2²
x=2
I hope this will help u ;)
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