SOLUTION: two consecutive numbers are added. The square of thier sum is 361. what are the intergers? (Quadratic equation)

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Question 1004156: two consecutive numbers are added. The square of thier sum is 361. what are the intergers? (Quadratic equation)
Found 2 solutions by mananth, macston:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let the two numbers be x & x+1
their sum = 2x+!
(2x+1) ^2 = 361
4x^2 +4x +1 =361
4x^2+4x -360 =0
/4
x^2+x-90=0
x^2 +10x-9x-90 = 0
x(x+10)-9(x+10)=0
(x+10)(x-9) =0
x = -10 or x = 9
the numbers are
-10,-9
OR
9 &10

Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
.
x=first number; x+1=second number
.
%28x%2Bx%2B1%29%5E2=361
2x%2B1%29%5E2=361
4x%5E2%2B4x%2B1=361
4x%5E2%2B4x-360=0
x%5E2%2Bx-90=0
%28x-9%29%28x%2B10%29=0
x-9=0 OR x%2B10=0
x=9 OR x=-10
The first number is 9 or -10.
.
ANSWER: The two numbers are 9 and 10 or -10 and -9.
.
CHECK:
For 9 and 10:
%289%2B10%29%5E2=361
19%5E2=361
361=361
.
For -10 and -9:
%28-10%2B%28-9%29%29%5E2=361
%28-19%29%5E2=361
361=361