(b) We have, y = 5
x2 + 24x - 28 ............(i)
and y = 3
x2 - 3x - 118 ....................(ii)
From Eq. (i). y = 5
x2 + 24x - 28 put in Eq. (ii), we get
5
x2 + 24x - 28 = 3
x2 - 3x - 118
⇒ 2
x2 + 27x = - 90
⇒ 2
x2 + 27x + 90 = 0
⇒ 2
x2 + 15x +12x + 90 = 0
⇒ x(2x + 15)+6(2x + 15) = 0
⇒ (2x + 15) (x + 6 ) = 0
∴ x =
− , - 6
Put x =
− in Eq. (ii), we get
y = 3 ×
−3×−()−118=+−118 =Now, put x = - 6 in Eq. (ii), we get
y = 36 x 3 - 3 x (-6 ) - 118
= 108 + 18 -118
= 8
So, the coordinate pairs are (-6 , 8 ) and
(−,)