Prove the sum of three consecutive is divisible by three, that the sum of 5 consecutive integers is divisible by 5, but the sum of four consecutive integers is not divisible by 4

Respuesta :

Answer:

Proved

Step-by-step explanation:

Solving (a):

Let the numbers be: [tex]x, x + 1, x + 2.[/tex]

Their sum is:

[tex]Sum = x + x + 1 + x + 2[/tex]

Collect Like Terms

[tex]Sum = x + x + x + 1 + 2[/tex]

[tex]Sum = 3x + 3[/tex]

Divide sum by 3.

[tex]Result = \frac{Sum}{3}[/tex]

[tex]Result = \frac{3x+3}{3}[/tex]

[tex]Result = \frac{3(x+1)}{3}[/tex]

[tex]Result = x + 1[/tex]

Hence, this is true because there is no fractional part after the division

Solving (b):

Let the numbers be: [tex]x, x + 1, x + 2,x+3,x+4[/tex]

Their sum is:

[tex]Sum = x + x + 1 + x + 2+x + 3 + x + 4[/tex]

Collect Like Terms

[tex]Sum = x + x + x + x + x+1 + 2 + 3 + 4[/tex]

[tex]Sum = 5x+10[/tex]

Divide sum by 5.

[tex]Result = \frac{5x + 10}{5}[/tex]

[tex]Result = \frac{5(x + 2)}{5}[/tex]

[tex]Result = x + 2[/tex]

Hence, this is true because there is no fractional part after the division

Solving (c):

Let the numbers be: [tex]x, x + 1, x + 2,x+3[/tex]

Their sum is:

[tex]Sum = x + x + 1 + x + 2+x + 3[/tex]

Collect Like Terms

[tex]Sum = x + x + x + x + 1 + 2 + 3[/tex]

[tex]Sum = 4x+6[/tex]

Divide sum by 4.

[tex]Result = \frac{4x + 6}{4}[/tex]

Split

[tex]Result = \frac{4x}{4} + \frac{6}{4}[/tex]

[tex]Result = x + 1.5[/tex]

The 1.5 means that the sum can not be divisible by 4