Which of the system(s) below works best to solve by elimination? Why? System 1 : 3m+n=71 2m-n=30 System 2 : 4x+y=1 y=-2x+9
System 3 : 5x+4y=15 5x + 11y=22

first option is easiest since it involves just adding both equations term by term.

3m+n=71

2m-n=30

Step-by-step explanation:

The first system looks like the easiest one, because the two equations are listed already in standard form, and the variable "n" appears as positive "n" in the first equation, and as its opposite "-n" in the second equation. Therefore the elimination method works directly by adding both equations term by term (thus cancelling out completely one of the variables in the resultant/combined equation.

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.