The coefficient of x in the quadratic equation ax2+bx+c=0 was wrongly taken as 17 in place of 13 and its roots were found to be –2 and –15, the actual roots of the equation are
–3 and –10
∴ Quadratic equation with roots −2,−15 is given by (x+2)(x+15)=0
⇒x2+17x+30=0
Correct quadratic is obtained by replacing 17 by 13.
⇒x2+13x+30=0
⇒(x+3)(x+10)=0
⇒x= –10,–3
Hence, actual roots are –3,–10.