How would i solve these? can some one show me the steps

1. a=bc+d solve for c
2. b1=r sy/sx solve for r

1. a=bc+d
-d -d
a-d=bc
/b /b
(a-d)/b=c

2. b1=r sy/sx
xSX xSX
sx(b1)= r sy
/sy /sy
sx(b1)/sy=r

1.bc=a-d, so c=(a-d/b)

2.sx(b1) =rsy, so r=(sxb/sy), so r=xb/y