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Find three consecutive integers such that the square of the first, increased by the last, is 32.

User Lajos Nagy
by
4.6k points

1 Answer

1 vote

Answer:


\huge\boxed{5, 6, 7}

Explanation:

In order to find the 3 consecutive digits here, we need to note that consecutive numbers are numbers that appear as the number right above each other.

For example: 2, 3, 4 are consecutive, as are -10, -9, -8.

We can assign the first term a variable, let's do x. Since we know the next two terms are consecutive, we can define them with
x+1 and
x+2.


x, (x+1), (x+2)

We also know that the first number squared, increased by the last, is 32. This can be modeled by the equation


x^2 + (x+2) = 32

Let's solve for x in that equation by using the XBOX Method in quadratics.


  • x^2 + x + 2 = 32

  • x^2 + x - 30 = 0
  • The product of the two roots will be c (-30) and their sum will be b (1).

  • -5 \cdot 6 = -30

  • -5 + 6 = 1

  • (x-5)(x+6)
  • Zeroes of the function:
    5, -6

Now that we know two values of x that might work, we need to plug them into our equation to test if they actually do work.

5


5^2 + (5+2) = 32\\\\ 25 + 7 = 32 \ \checkmark

-6


-6^2 + (-6+2) = 32 \\\\ -36 + -4 = 32 \ *

We can see here that -6 won't work as it doesn't satisfy our equation. However, 5 does work. That means our first number is 5, making our next two numbers 6 and 7.

Hence - 5, 6, 7.

Hope this helped!

User Joe Hildebrand
by
4.1k points