Question

I need help with both of them 3&4

Answer 1

3)
`(c)/(a)` = r - d Multiply both sides by a

c = a (r - d) Divide both sides by (r - d)

`(c)/(r - d)` = a Switch the sides to make it easier to read

a =
`(c)/(r - d)`

4) z = xm + y Subtract y from both sides

z - y = xm Divide both sides by m

`(z - y)/(m)` = x Switch the sides to make it easier to read

x =
`(z - y)/(m)`