The values of y which will satisfy the equations 2x2 + 6x + 5y + 1 = 0 2x + y + 3 = 0 may be found by solving:
Explanation:
2x2 + 6x + 5y + 1 = 0 ∴ 2x(x + 3) + 5y + 1 = 0 ...(1)
Also, 2x + y + 3 = 0 ∴ 2x = – (y + 3) ...(2) ∴ x = (-(y+3))/2 ...(3)
Substituting (2) & (3) in (1), -(y + 3)-(y+3)2+3 + 5y + 1 = 0
∴ -(y+3)(-y-3+6)2 + 5y + 1 = 0
∴ –(y + 3) (–y + 3) + 10y + 2 = 0
∴ –(9 – y2) + 10y + 2 = 0
∴ y2 + 10y – 7 = 0
Hence, option (c).
» Your doubt will be displayed only after approval.
Help us build a Free and Comprehensive Preparation portal for various competitive exams by providing us your valuable feedback about Apti4All and how it can be improved.