Question

What is the solution to the equation 2^x+4 -12=20?

A. x=0
B. x=1
C. x=2
D. x=9

Answer 1

2^x+4 -12=20
2^x+4 = 20+12
2^x+4 = 32
2^x+4 = 2^5
x+4 = 5
x = 1

answer is B. x=1

Answer 2

Given: The equation
`2^(x+4) -12=20\\`

To Find: The value of x

Solution:
`x=1`

Calculation/Explanation:

We simplify the given equation in the usual way, as follows:

`2^(x+4)-12=20\\2^(x+4)=20+12\\2^(x+4)=32\\2^(x+4)=2^(5)\\`

Now, we use the property that if two sides of the equation are equal and have the same base, then the exponents too must be equal.

So we have

`2^(x+4) =2^(5)\\x+4=5\\x=1`

Therefore option B is correct, i.e.,
`x=1`