rewrite each equation in polar form. solve for r if possible

Question

a. 2x+3y=5
b. y=1/2x

Answer 1

2rcosθ + 3rsinθ = 5
r = 5/(2cosθ+3sinθ)

rsinθ = 1/2 rcosθ
tanθ = 1/2
θ = arctan(1/2)
No r involved.