Answer:
1. 15, 16, 17
2. 21, 23, 25
3. 44, 46, 48
4. -4, -3, -2
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.