First, divide both sides of the equation by 4:
4×22x+1=80 22x+1=480 22x+1=20 Next, we can take the logarithm of both sides. Let's use the base-2 logarithm.
log2(22x+1)=log2(20) Using the logarithm property logb(ac)=c⋅logb(a), we get: (2x+1)log2(2)=log2(20) Since log2(2)=1, we have: 2x+1=log2(20) Subtract 1 from both sides:
2x=log2(20)−1 Divide both sides by 2:
x=2log2(20)−1 We can express log2(20) as log2(4×5)=log2(4)+log2(5)=log2(22)+log2(5)=2+log2(5). Therefore,
x=22+log2(5)−1=21+log2(5) We can rewrite this as:
x=21+2log2(5)=21+21log2(5)=21+log2(51/2)=21+log2(5). Alternatively, we can find an approximate value using a calculator.
x=2log2(20)−1. We know that 24=16 and 25=32, so log2(20) is between 4 and