Question 634473: The sum of the square of a positive number and the square of 4 more than the number is 58 what is the number? Answer by ptaylor(2198) (Show Source):
You can put this solution on YOUR website! Let x= the positive number; x^2=the square of the positive number
x+4= four more than the number; (x+4)^2=the square of 4 more than the positive number
Now we are told that:
x^2+(x+4)^2=58 simplify
x^2+x^2+8x+16=58
2x^2+8x+16=58
2x^2+8x-42=0 divide each term by 2
x^2+4x-21=0---quadratic in standard form and it can be factored
(x+7)(x-3)=0
x=-7 and
x=+3---------------------------answer (problem calls for positive number)
CK
3^2+7^2=58
9+49=58
58=58
Hope this helps--ptaylor
