Explanation:
for 1:
we know that bc+cd=bd
plug in what we wre given
23+22= bd
add.
for 2:
we know that ef+fg=eg
plug in what we know
4x+3 + 6x+9 = 72
combine like factors
10x+12=72
solve
(subtract 12 on both sides) 10x=60
(divide by 10 on both sides) x=6