For this case we must algebraically rewrite the given expression. So:
x: It is the variable that represents an unknown number
"double a number" is represented as: 
"6 less than double a number" is represented as: 
So, the final expression is:
If we want to rewrite the expression in an equivalent way, we take common factor 2:
Asnwer:
Equivalent expression:
Answer:
it should be (-8, -7)
Step-by-step explanation:
look up a coordinate plane
Answer:
4 units ...................
Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
Yes, 3 yards is bigger than 21 feet because there are 3 feet in a yard.
