SOLUTION: The product of two consecutive integers is 20. Find the integers.

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: The product of two consecutive integers is 20. Find the integers.       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 913506: The product of two consecutive integers is 20. Find the integers.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x = first number

x+1 = second number


x%2A%28x%2B1%29+=+20

x%5E2%2Bx+=+20

x%5E2%2Bx-20=0

Use the quadratic formula to solve for x

x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29

x+=+%28-%281%29%2B-sqrt%28%281%29%5E2-4%281%29%28-20%29%29%29%2F%282%281%29%29 Plug in a+=+1, b+=+1, c+=+-20

x+=+%28-1%2B-sqrt%281-%28-80%29%29%29%2F%282%29

x+=+%28-1%2B-sqrt%281%2B80%29%29%2F%282%29

x+=+%28-1%2B-sqrt%2881%29%29%2F2

x+=+%28-1%2Bsqrt%2881%29%29%2F2 or x+=+%28-1-sqrt%2881%29%29%2F2

x+=+%28-1%2B9%29%2F2 or x+=+%28-1-9%29%2F2

x+=+8%2F2 or x+=+-10%2F2

x+=+4 or x+=+-5

If you're only considering positive numbers, the two numbers are 4 and 5

Let me know if you need more help or if you need me to explain a step in more detail.
Feel free to email me at jim_thompson5910@hotmail.com
or you can visit my website here: http://www.freewebs.com/jimthompson5910/home.html

Thanks,

Jim