Colin was thinking of a number. Colin halves it and gets an answer of 5.2. What was the original number?

10.4

Step-by-step explanation:

Let the number that Colin is thinking of be represented as x.

We are informed that Colin halves the number and gets an answer of 5.2. This can be written as:

x ÷ 1/2 = 5.2

0.5x = 5.2

Divide through by 0.5

0.5x/0.5 = 5.2/0.5

x = 10.4

The number is 10.4

x =-.20752

step-by-step explanation:

4^(x+2)=12

4^(x+2)=12

take the log base 4 on each side

log 4 (4^(x+2) = log 4(12)

we know log b(a^y) = y log b (a)

(x+2) log 4(4) = log 4 (12)

x+2 = log 4 (12)

we know   logb c = loga c/loga b

we want to convert to base 10   so a = 10

by default, we do not write the 10   c = 4   and b = 10

log4 10 = log 12/log 4

log4 10 = log 12/ log 4

x+2 = log 12/ log 4

subtract 2 from each side

x +2 -2 = log 12/ log 4 -2

x = 1.79248125 -2

x =-.20752