Complete the page for 15 points.

1. 15, 16, 17

2. 21, 23, 25

3. 44, 46, 48

4. -4, -3, -2

Step-by-step explanation:

1)

Step 1. Writing an equation

Let's set x as the second number in the equation.

This means that the first number is x-1, and the third number is x+1.

We know that the sum of the three numbers is 48, so:

(x-1)+x+(x+1)=48

Step 2. Solving the equation

x-1+x+x+1=48

x+x+x-1+1=48

3x=48

x=16

So the answer is 15, 16, 17

2)

Again, let's set x as the middle number.

Odd numbers are 2 numbers apart, so the first number is x-2, and the third is x+2.

This means that the equation must be:

(x-2)+x+(x+2)=69

x+x+x=69

3x=69

x=23

The numbers are 21, 23, and 25

3)

x will be the middle number

Even numbers are 2 numbers apart, so the first number is x-2, and the third is x+2.

This means that:

x-2+x+x+2=138

x+x+x=138

3x=138

x=46

The numbers are 44, 46, and 48.

4)

x will be the middle number.

x-1=first number, x+1=third number

x-1+x+x+1=-9

3x=-9

x=-3

The numbers are -4, -3, and -2.