What are the answers to these questions ?

7a=49
a=49/7
a=7
-6=2x
x=-6/2
x=-3
-32=-4b
B=-32/-4
B=8
u/6=9
u=9*6
u=54
-8=C/-10
c=-8*-10
C=80
54=-9d
D=54/-9
D=-6
-12y=60
y=60/-12
y=-5
r/20=-2
r=-2*20
r=-40
g/10=-9
g=-9*10
g=-90
cost of the camera =$300
her weekly savings=$15
15x=300
x=300/15
x=20
in 20 weeks she will have enough money to buy the camera
speed of a race car= 205mph
distance travelled in three hours = x
r=D/t
d=r*t
speed = distance/time
distance = speed * time
x=205*3
x=615miles