Answer:
3x+y=8 and 3x+y=9
Step-by-step explanation:
Assume these two equations:
a1x+b1y+c1=0
a2x+b2y+c2=0
If (a1/a2) = (b1/b2) ≠ (c1/c2) than those two would have no solution.
In these case, take a look at the last option:

Re-write 'em as a standard form:

So (a1/a2) = (b1/b2) ≠ (c1/c2) is true here:

And they do not have any collision point
The probability that a girl will be selected from the class is 0.7
4 gallons × y dollars/gallon=$6.76
4y=6.76
Divide both sides by 4
Y=$1.69