Question

Solve each of the following pairs of equations by the elimination method.
$3x+4y=25$
$5x-6y=-9$

Answer 1

$3x+4y=\mathrm{25.......}\left(i\right)$

$5x-6y=-9$

$x=\frac{6y-9}{5}$

Put $x$ in $\left(i\right)$

$3\left(\frac{6y-9}{5}\right)+4y=25\frac{18y-27+20y}{5}=2538y=125+27y=\frac{152}{28}=4x=\frac{6y-9}{5}=\frac{6\left(4\right)-9}{5}=3$