I need math help?

Question

1. A girl scout troop sold cookies. If the girls sold 5 more boxes the second week than they did the first, and if they doubled the sales of the second week for the third week to sell a total of 431 boxes of cookies, how many did they sell each week?

2.The four oldest people in Golden City have lived a total of 384 years put together. The difference in ages for the youngest and the second oldest is 14. The second youngest is 3 years older than the youngest. The oldest is 20 years older than the average of the second oldest and youngest. What are their ages?

3.Four numbers have a total of 92. The first number is twice the second number and the third number is 4 more than the sum of the first two. The fourth number is 3 less than the difference of the first two numbers. What are the numbers?

Answer 1

For number 1 - this is a simple algebra problem. X is the number of boxes sold the first week; X + 5 is the number sold the second week; 2(X+5) is the number sold the 3rd week; thus

X + 5+X + 2(X+5) = 431 thus;

2X + 5 + 10 + 2X = 431;
4x + 15 = 431;
4x = (431-15)
4x = 416
x= 104

To check your answer put 104 in for each X in the equation and you will see that when added it will total 431 boxes sold.

Answer 2

1. let x = boxes of cookies sold on week 1
x+5 = boxes of cookies sold on week 2
2(x+5) = boxes of cookies sold on third week

x + (x+5) + 2(x+5) = 431
x + x + 5 + 2x + 10 = 431
4x + 15 = 431
4x = 431 - 15
4x = 416
x = 104 (first week)
x+5 = 109 (second week)
2x + 10 = 118 (third week)

2. x : youngest
x + 14 : second oldest
x + 3 : second youngest
20 + (x + x + 14)/2 = x + 27 : oldest
if sum of all ages is 384 then
x + (x+14) + (x+3) + (x + 27) = 384
4x + 44 = 384
4x = 340
x = 85 youngest
x + 3 = 88 second youngest
x + 14 = 99 second oldest
x + 27 = 112 oldest

3.
2x : first number
x : second number
2x + x + 4 = 3x + 4 : third number
(2x - x) - 3 = x - 3 : fourth number

2x + x + (3x + 4) + (x - 3) = 92
7x + 1 = 92
7x = 91
x = 13 (second number)
2x = 26 (first number)
3x + 4 = 43 (third number)
x - 3 = 10 (fourth number)

Answer 3

1. Let x = the number sold the first week.

x + x+5 + 2(x+5) = 431
4x + 15 = 431
x = 104.25 ???? Is this the right question?

2. Let x = the age of the second oldest
x + x+14 + x + 3 + (x+14+x)/2 + 20 = 384
4x + 41 = 384
x = 85.75????

x + 2x + (x+2x)+4 + 2x-x-3 = 92
7x + 1 = 92
7x = 91
x = 13

Answer 4

I am not putting the answers because you are probably lazy. They give you homework to practice, not to go on Yahoo! Answers to ask random people how to do it.

Answer 5

1. 68
2.45634