90*b+50=230
90*b=230 -50
90*b=180
b=180:90
b=2
1400:y-29=41
1400:y =41+29
1400:y =70
y=1400:70
y=20
(900-x:6)*5=4200
900-x:6=4200:5
900-x:6=840
x:6=900-840
x:6=60
x=60*6
x=360
325+(90-n):17=330
(90-n):17=330-325
(90-n):17 =5
90-n= 5*17
90-n= 85
n=90-85
n=5
