English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

Find three even cosecutive integers such that the sum of the smallest and twice the second is 20 more than the third

2006-12-30 10:46:28 · 7 answers · asked by patrick 1 in Science & Mathematics Mathematics

7 answers

Three even consecutive integers:

x, x + 2, x + 4

Such that the sum of the smallest and twice the second:

x + 2(x + 2)

is 20 more than the third:

x + 2(x + 2) = x + 4 + 20
x + 2x + 4 = x + 24
2x = 20
x = 10

So the integers are 10, 12, and 14.

Check: 10 + 2(12) = 14 + 20 check!

2006-12-30 10:50:32 · answer #1 · answered by Jim Burnell 6 · 3 0

let the smallest number = x
the middle number would then be equal to = x+2 since the difference bet. any two POSITIVE integers is 2.
then the largest number would be x+2+2= x+4

the equation:

x + 2(x+2) = x + 4 + 20 (simplify them to get:
x + 2x + 4 = x + 24 (combine like terms to get:
3x - x = 24 - 4 (simplify again to get:
2x = 20 (divide both sides by 2 to have:
x = "10"

substitute the values:
x=10;
x+2= 10+2 = "12"
x+4= 10+4 = "14"

check: x=10

x + 2(x+2) = x + 4 + 20
10 + 2(10+2) = 10 + 4 + 20
10 + 2(12) = 34
10 + 24 = 34
34 = 34
checked! since 34 is 20 more than the third number 14..

2006-12-30 19:49:45 · answer #2 · answered by naz0711 2 · 0 0

Start with x, x + 2, x + 4. Then x + 2(x+ 2) = 20 + (x + 4) => x + 2x + 4 = x + 24 => 3x + 4 = x + 24 => 2x = 20 => x = 10, x + 2 = 12, and x + 4 = 14.

2006-12-30 19:44:37 · answer #3 · answered by flyfisher_20750 3 · 0 0

To solve this you need to make an equation.

Let ABC be the consecutive numbers

B = A + 2
C = A + 4
Because the numbers are consecutive

A + 2B = C + 20

A + 2(A + 2) = (A + 4) + 20
A + 2A + 4 = A + 24
3A + 4 = A + 24
Put the terms on their own sides by subtracting both sides by A and 4.
2A = 20
Divide by two
A = 10
B = 10 + 2 = 12
C = 10 + 4 = 14
So the consecutive numbers are 10, 12, and 14.

2006-12-30 18:53:18 · answer #4 · answered by Roman Soldier 5 · 0 0

n+2(n+2)=n+4+20
3n+4=n+24
2n=20
n=10
numbers are 10, 12, 14

check
10+2*12=34
14+20=34

2006-12-30 19:08:27 · answer #5 · answered by yupchagee 7 · 0 0

n+2(n+2)=n+4+20
n+2n+4=n+24
2n=20
n=10
10,12,14

2006-12-30 18:53:46 · answer #6 · answered by Kristin E 2 · 0 0

first number is x
second number is y
third number is z

x+2y=z
y=x+2
z=y+2

use substitution to figure it out... shouldn't be that hard.

2006-12-30 18:50:26 · answer #7 · answered by northwestsk8 1 · 1 0

fedest.com, questions and answers