SOLUTION: Either factor or use the quadratic formula to solve the given equation. 2^2x − 8(2^x) + 15 = 0

Question 957760: Either factor or use the quadratic formula to solve the given equation.
2^2x − 8(2^x) + 15 = 0

Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Either factor or use the quadratic formula to solve the given equation.
2^2x − 8(2^x) + 15 = 0
***
let u=2^x
u^2=2^2x
u^2-8u+15=0
(u-5)(u-3)=0
..
for u=5
5=2^x
xlog2=log5
x=log5/log2=2.3219
or
For u=3
3=2^x
xlog2=log3
x=log3/log2=1.5850
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SOLUTION: Either factor or use the quadratic formula to solve the given equation. 2^2x &#8722; 8(2^x) + 15 = 0