addition/subtraction
1z+2z+=
3z
if v=10 then 3v+4v
70=v
d+10=50
d=40
5w=10
w=5
a/8=10
a=80
a=6=16
subtract 6 from each side
21z-10z
11z
if n=25 then 2n+8n
n=250
40+t=100=
t=60
15w=45
w=3
a/7=9
a=63
a-20=40
add 20 to each side
106z-21z
85z
if q=2 q=10q
q=22
p-9=17
p=26
50w=350
w=7
a/5=9
a=45
12=d-20
add 20 to each side
173z+21z=
194z
if l=5 10-l=
l=5
p-137=37
p=174
27w=2484
a/2=2692
a=1346
35=r+10
subtract 10 from each side
178z-10z=
168z
if t=10 100-10
t-90
150-20=c=45
c=85
50w=22250
w=445
a/4=7680
a=1920
a+1000678=1000679
subtract 1000678 form each side