Combine like terms to create a equivalent expression to
2r+1+(-4r)+7

-2r+8

Step-by-step explanation:

Add 1 and 7 to get    2r+8+(-4r)

Then subtract 4r from 2r because adding a negative is the same as subtracting. so that makes your answer      -2r+8  

step-by-step explanation:

no of data

divide by no of mode

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.