It seems confusing, but it's just breaking down the steps for you. It's done the same as any other word problem.
a. The unknown is how many minutes she used beyond the plan. So, we'll use "m" for the variable, to represent minutes.
b. 73.40 = 65 + 0.10m
The 73.40 is the total, which is why it's by itself. 65 represents the price per month for the plan, and 0.10m is the price per extra minute multiplied by the unknown amount of minutes used.
c. 73.40 = 65 + 0.10m
8.40 = 0.10m
84 = m
d. The number of minutes that Allegra went over the time that the plan allows is found by solving the equation we just wrote and solved. $0.10 is paid for every minute past the plan's allowance, meaning that "m" in the equation, when solved, shows us exactly how many minutes over Allegra went.
40/100= 56/x
40x=100(56)
40x=5600
Divide both sides by 40 to get x alone.
X=140
Number 4 and 6 are correct because you can only add variables with other variables so that is why 4 and 6 are correct
There is a formula for adding consecutive numbers:
total = n*(n+1)/2
total = 80*(81)/2
total = 3,240
