Question

please answer this quadratic sum..easy one .THE ANSWER IS 7 nd 49.

Answer 1

Hope this answer will help you
$let \: the \: age of \: son \: be \: x and \: father \: age \: be \: y \: \\on \: year \: ago \\ son \: age = x - 1 \\ father \: age = 8(x - 1) \\ y - 1 = 8x - 8 \\ y - 8x = 1 - 8 \\ y - 8x = - 7 ........(i) \\ now \: his \: age \:is \: the \: square \: of \: sons \: age \\ y = {x}^{2} .......(ii) \\ from \: equation \: i \: putting \: the \: value \: of \: y \\ {x}^{2} - 8x = - 7 \\ {x}^{2} - 8 x + 7 = 0 \\ {x}^{2} - 7x - x + 7 = 0 \\ x(x - 7) - 1(x - 7) = 0 \\( x - 1)(x - 7) = 0 \\ x - 1 = 0 \\ x = 1 \\ x - 7 = 0 \\ x = 7 \\ therefore \: son \: age \: is \: 7years \\ and \: father \: age = {7}^{2} = 49years$