A number squared + 1 is 26, what’s the number? Algebra Word Problem!

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[osgubben]

The day I cant calculate this in one second, please call the ambulance for me.

[nancyholcombe]

5. Know my multiplication tables at the age of 65 so no equation needed for me, just glad I can still remember them! 😊
Edit: They weren't teaching negative numbers when they taught the tables! Oops! -5 certainly is an answer as well.

[quaver]

Am 82, and even I could solve this in one second! Thank you. I feel really smart now. 😅

[HR-wdcw]

Subtract 1 and then try to figure out what squared is 25, which is 5. Actually figured this out from the thumbnail. Could also be -5 as well although my assumption is hat he figures that you know a negative x negative is a positive number (that's basic algebra). The one possible reason why -5 was not mentioned is there may be some instances where a negative value is not possible, such as if we were trying to find the dimensions of a room. -5 ft wouldn't work.

[dazartingstall]

x² + 1 = 26
x² = 25
√x² = √25
x = ±5

[Kleermaker]

What happened to the Principal Square Root? :) The answer is of course 5/-5. Two solutions (quadratic equation).

[timherbers]

subtract the one 25. 5x5 25. I know how to do all of this type of problem from years of working with partners. Take out the expenses then divide the rest according to the partner ship agreement.

[devonwilson]

Greetings. The number is 5. Let us assume that the number to be squared is X. Now, based on the details provided, we are are told that if we squared that number, X, and add 1 to it the result is equal to 26. Therefore, X^2 +1=26, and
X^2 =26-1,
(X^2)^1/2=+, - (25)^1/2. That is
X=5, -5.

[edmondeyeemceeezekiels]

You really challenged my intuition today mate

[bradlewis]

I knew it could be + or -, but I figured just put the + answer in to have less chance for confusing a very adolescent math interested learner. But I now know. Thank you for the consistent mind challenging and/ or insightful problems.

[mercy]

We have a number squared plus 1 is 26


1. First, we need convert this to an equation.


2. So, we have a number squared (we’ll call the number “x”); remember that when we say “number squared”, it just means some number, x, is being squared.


3. Then, we have plus 1, which means, well, plus 1 ( not much to say).


4. And we have “ is 26”, which means x² + 1 is equal to 26.


5. Now, we have the equation x² + 1 = 26. We find x.


x² + 1 = 26
x² = 25
x = ±√(25)
x = ± 5

Final ans: ±5

Ez

[cliftonbrown]

X^2+1=26
X^2+1-1=26-1
X^2=25
X=+-5
5^2=25
5^2+1=26

[vincentrobinette]

I didn't think of -5. It said "a" number, (singular)so I guessed +5. It does make sense though, -5 X -5 = 25, just the same. Add 1, to get 26.

[stevenjohnson]

Simple x^2+1=26 subtracting 1 from both sides x^2=25 taking the square root you x=-5 x=5

[thomasharding]

"A number squared + 1 is 26", therefore "A number squared" is 25 and the square root of "A number squared "is the square root 0f 26. So "A number" is +-5.

[chrisdissanayake]

Let x be the number.

x^2 + 1 = 26

x^2 = 26 - 1 = 25

x^2 = 25

x = square root of 25

x = +5 or x = -5

[Vipre-]

Subtract 1 and then find the square root.

[russelllomando]

got it +5 & -5 1 second thanks for the fun

[nashsingh]

Under two seconds to... 26-1=25. Square root of 25=5...

[Ayelmar]

Solved in my head at the thumbnail, took about 2 ro 3 seconds, bascially just long enough to read it, the answer is 5.
My thinking: "A number...squared...plus 1...is 26 -- 25 -- 5!"