AP EAMCET Engineering 22 Apr 2019 Shift 1 Paper

Consider the given equations,
3x2−7x+2=0 ....(I)
15x2−11x+a=0....(II)
Here,
a1=3,b1=−7,c1=2
a2=15,b2=−11,c2=a
If α be the common root, then it is given by,
(2(15)−3a)2=(−7a+22) (−33+105)
(30−3a2)=(22−7a)(72)
[9(10−a)2 ]=(22−7a)8
100+a2−20a=176−56a
a2+36a−76=0
a(a+38)−2(a+38)=0
a=2‌‌‌‌[∵a>0]
So, the sum of the roots of the equation 15x2−ax+7=0 can becalculated as,
Sum of roots =−

coefficient‌of‌x

coefficient‌of‌x2

=−

(−a)

15

=

a

15

=

2

15