Shaun is 4 years older than her sister charmaine. if the sum of their ages is 16 how old is charmaine?
a) 4 years old
b) 6 years old
c) 8 years old
d) 10 years old

The answer is B) 6 years

Step-by-step explanation:

First of all, build an equation. With the given problem, you can come up with:

s + c = 16

In which interprets that both their ages summed up are 16. Secondly,:

s = c + 4

After you will use the typical system of equations to solve. So, plug in the second equation to the first, where s will become c + 4, and the equation is now:

c + 4 + c = 16

And finally, solve for Charmaine's age.

2c + 4 = 16

    -4     -4

2c = 12

c = 6

2/3x + 7 = 29

step-by-step explanation:

two thirds = 2/3

plus a number = x

at least 29 = 29

there for you should get 2/3x + 7 = 29