SOLUTION: Find two integers, x and x + 1, whose squares differ by 25.

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Question 117950: Find two integers, x and x + 1, whose squares differ by 25.
Found 3 solutions by MathLover1, bucky, jim_thompson5910:
Answer by MathLover1(20849)   (Show Source): You can put this solution on YOUR website!
two integers;
and , whose squares differ by








and





Answer by bucky(2189)   (Show Source): You can put this solution on YOUR website!
The two unknown integers are represented by x and by x+1
.
If you square the two integers you get:
.

and

.
Squaring results in
.
If you subtract the two squares, the problem tells you that the result is 25. In equation form
this subtraction can be expressed as:
.

.
Notice that in the subtraction the two terms are of opposite sign and therefore
cancel each other. Therefore, you are left with:
.

.
Get rid of the 1 on the left side by subtracting 1 from both sides to get:
.

.
Solve for x by dividing both sides of this equation by 2 to reduce the equation to:
.

.
So one of the unknown integers (that is x) equals 12. The other integer is x + 1 and therefore
it equals 12 + 1 or 13.
.
The two integers you are looking for are 12 and 13.
.
Check. 12 squared is 144 and 13 squared is 169. The difference is 169 - 144 = 25, just as the
problem requires. So this answer checks and the two integers are 12 and 13.
.
Hope this helps you to understand the problem.
.

Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
If their squares differ by 25, then we have the equation


Start with the given equation


Foil


Combine like terms



Subtract 1 from both sides


Combine like terms on the right side


Divide both sides by 2 to isolate x



Divide

--------------------------------------------------------------
Answer:
So our answer is



Now add 1 to 12 to get the next number. So


This means our two numbers are 12 and 13


Check:

Start with the given equation

Plug in the solution

Square each term

Subtract. Since the two sides of the equation are equal, this verifies our answer.

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