X^2-3 (x+3)=0

Asked by Pynebiswajit | 17th Dec, 2018, 09:49: AM

Expert Answer:

 
x2 - 3x - 9 = 0
D = b2 - 4ac = (-3)2 - 4 × 1 × (-9) = 9 + 36 = 45
begin mathsize 16px style straight x space equals space fraction numerator negative straight b space plus-or-minus space square root of straight D over denominator 2 straight a end fraction equals space fraction numerator negative left parenthesis negative 3 right parenthesis space plus-or-minus space square root of 45 over denominator 2 space cross times space 1 end fraction space equals space fraction numerator 3 plus-or-minus space square root of 9 space cross times space 5 end root over denominator 2 end fraction space equals space fraction numerator 3 plus-or-minus space 3 square root of space 5 end root over denominator 2 end fraction
straight x space equals space fraction numerator 3 plus space 3 square root of space 5 end root over denominator 2 end fraction space or space straight x space equals space fraction numerator 3 minus space 3 square root of space 5 end root over denominator 2 end fraction end style 
 

Answered by Yasmeen Khan | 17th Dec, 2018, 10:05: AM