Question

Solve the following simultaneous equation graphically 1.2x-y=12: x+3y=1

Answer 1

$2x - y = 12 - - - - - (1)$

$x + 3y = 1 - - - - - (2)$

$2 \times eq(2) - eq(1)$

$\binom{2x + 6y = 2}{ - 2x + y = - 12} = > 7y = - 10$

$|y = - \frac{10}{7} |$

$sub \: y \: in \: eq(1)$

$2x - ( - \frac{10}{7} ) = 12 = > 2x + \frac{10}{7} = 12$

$2x = 12 - \frac{10}{7} = > 2x = \frac{84 - 10}{7} = > 2x = \frac{74}{7}$

$x = \frac{74}{7 \times 2} = > \frac{37}{7}$

$|x = \frac{37}{7} |$