Answer:
It appears to be substitution
Step-by-step explanation:
I think you are talking about system of equations
825 miles to drive 15 hours
Answer:
there's one graph I don't see the others
Answer:

Step-by-step explanation:

we can use the distributive property and get

and we can add like terms

and know we divide both sides by 16.5

and doing the dvision we get that

Identity property of addition