SOLUTION: Over the last 3 evenings, Latoya received a total of 77 phone calls at the call center. The third evening, she received 5 fewer calls than the first evening. The second evening

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: Over the last 3 evenings, Latoya received a total of 77 phone calls at the call center. The third evening, she received 5 fewer calls than the first evening. The second evening      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1079944: Over the last 3 evenings, Latoya received a total of
77 phone calls at the call center. The third evening, she received
5 fewer calls than the first evening. The second evening, she received
2 times as many calls as the third evening. How many phone calls did she receive each evening?

Found 2 solutions by Boreal, Theo:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
first evening is x
third evening is x-5
the second evening is 2(x-5)=2x-10
They add to 77
x+x-5+2x-10=77
4x-15=77
4x=92
x=23 first evening
2x-10=36 second evening
x-5=18 third evening

Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
she received 77 calls total.

let x = the number of calls she received the first evening
let y = the number of calls she received the second evening.
let z = the number of calls she received the third evening.

x + y + z = 77

the third evening she received 5 fewer calls than the first evening.

z = x - 5

the second evening she received 2 times as many call as as the third evening.

y = 2z

you have the following 3 equations that need to be solved simultaneously,

x + y + z = 77
z = x - 5
y = 2z

you want to eliminate 2 of the variables in the first equation so you can solve for the third.

replace z with x - 5 in the first equation to get:

x + y + x - 5 = 77

combine like terms to get:

2x + y - 5 = 77


in the equation of y = 2z, replace z with x - 5 to get:

y = 2 * (x - 5)

simplify to get y = 2x - 10

in the equation of 2x + y - 5 = 77, replace y with 2x - 10 to get:

2x + 2x - 10 - 5 = 77

combine like terms to get:

4x - 15 = 77

add 15 to both sides of the equation to get:

4x = 92

divide both sides of the equation by 4 to get:

x = 23

you started with:

x + y + z = 77
z = x - 5
y = 2z

since x = 23, these equations became:

24 + y + z = 77
z = 23 - 5 = 18
y = 2z = 2 * 18 = 36

you have:

x = 23
y = 36
z = 18

x + y + z becomes 23 + 36 + 18 = 77
z = x - 5 becomes z = 23 - 5 = 18
y = 2z becomes y = 2 * 18 = 36

solution looks good.