Which system has no solution? a. y=-3x+8 6x+2y=4.5 b. y=9x+6.25 -18x+2y=12.5 c. y=4.5x-5 -3x+2y=6 d. y=3x+9 x+8y=12.3

we have that

case a)

y=-3x+8 > equation 1

6x+2y=4.5--> 2y=-6x+4.5--> divide by 2 both sides--> y=-3x+2.25--> equation 2

equation 1 and equation 2 are parallel

because the slopes are the same

m=-3

so

the system has no solution

case b)

y=9x+6.25 > equation 1

-18x+2y=12.5> 2y=18x+12.5> divide by 2 both sides> y=9x+6.25--> equation 2

equation 1 and equation 2 are the same

so

the system has infinite solutions

case c)

y=4.5x-5 > equation 1

-3x+2y=6> equation 2

substitute equation 1 in equation 2

-3x+2*[4.5x-5]=6> -3x+9x-10=6> 6x=16> x=2.67

y=4.5*(2.67)-5> y=7

the system has the solution (2.67,7)

case d)

y=3x+9 > equation 1

x+8y=12.3> equation 2

substitute equation 1 in equation 2

x+8*[3x+9]=12.3> x+24x+72=12.3> 25x=12.3-72> x=-2.39

y=3*(-2.39)+9> y=1.84

the system has the solution (-2.39,1.84)

therefore

the answer is

the system A has no solution

is only a line? i think so