# How do you solve 9c + 2d = 54 and  c + 2d = 6?

May 21, 2018

$c = 6 , d = 0$

#### Explanation:

$9 c + 2 d = 54 - - - - - \left(1\right)$

$c + 2 d = 6 - - - - - - \left(2\right)$

$\therefore \left(1\right) - \left(2\right)$

$\therefore 8 c = 48$

$\therefore c = {\cancel{48}}^{6} / {\cancel{8}}^{1}$

$\therefore c = 6$

substitute c=6 in (2)

$\therefore \left(6\right) + 2 d = 6$

$\therefore 6 + 2 d = 6$

$\therefore 2 d = 6 - 6$

$\therefore 2 d = 0$

$\therefore d = 0$

~~~~~~~~~~~~~

substitute c=6 and=0 in (1)

$\therefore 9 \left(6\right) + 2 \left(0\right) = 54$

$\therefore 54 + 0 = 54$

$\therefore 54 = 54$