Which set of scores has the greatest variance? A) 80,89,98,112 B) 57,57,59,56 C) 20,39,43,60 D) 17,19,23,25 Please show work! Thank you

Can some one me with these questions

2x minus y equals 6, x plus y equals negative 3

Jude is making cement for a driveway. the instructions show the amount of each ingredient to make 1 batch of cement. complete each statement to adjust the ingredients for each new situation if jude uses these instructions.