Question

Find the co-ordinates of the point whose abscissa is the solution of the first equation and ordinate is the solution of the second equation.

Answer 1

$3 - 2x = 7 \\ - 2x = 7 - 3 = 4 \\ x = \frac{4}{ - 2} = - 2 \: \\ abscissa = - 2$

$2y + 1 = 10 - 2 \frac{1}{2} y \\ 2y + 1 = 10 - \frac{(2 \times 2 \: + 1)}{2} \:y \\ 2y + 1 = 10 - \frac{5}{2} y \\ 2y - \frac{5}{2} y = 10 - 1 \\ y( \frac{4 - 5}{2} ) = 9 \\ y (\frac{ - 1}{2} ) = 9 \\ y = - 18 \\ ordinate = - 18$