Which steps are needed to solve this equation?
b+6= 21
Subtract 6 from both sides of the equation.
The answer is b= 15.
Check the solution by substituting 15 for b.
Subtract 6 from the left side and add 6 to the right side of the equation.
The answer is b= 27.
Check the solution by substituting 27 for b.
Add 6 to both sides of the equation.
The answer is b= 27.
Check the solution by substituting 27 for b.
Add 6 to the left side and subtract 6 from the right side of the equation.
The answer is b-15.
Check the solution by substituting 15 for b.

A- Subtract 6 from both sides of the equation.  The answer is b= 15.

For this equation, you need to do the opposite of the number in the same side of the variable. So, there is a +6. To get rid of the +6, you need to be -6.

6-6=0

21-6=15

You will be left with b on one side, and then 15 on the other side.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)