Which linear equation shows a proportional relationship?
a y equals negative 2 times x minus one fifth
b y equals two thirds times x minus 1
c y equals 4 times x plus 6
d y equals three fourths times x
a y equals negative 2 times x minus one fifth
b y equals two thirds times x minus 1
c y equals 4 times x plus 6
d y equals three fourths times x