$$4 \times +3=21-2x$$
$x = \frac{9}{2} = 4\frac{1}{2} = 4.5$
$$12=21-2x$$
$$21-2x=12$$
$$-2x=12-21$$
$$-2x=-9$$
$$x=\frac{-9}{-2}$$
$$x=\frac{9}{2}$$
Show Solution
Hide Solution
