Answer:
C. Create a pair of equations with different slopes. ( Holds only if the equations are linear, otherwise they can have more than one solution)
E. Create a pair of lines that intersect at only one point.
Explanation:
Intersection points of two lines are the solutions for the equation, because intersection points satisfy both equations.
Also assuming the equations are linear, creating a pair of equations with different slopes has one solution as the example below:
assume line1 is ax+b and line2 is cx+d
then ax+b=cx+d has a solution at x=(d-b)/(a-c) given that a≠c