I believe the answer is A
Answer:
1
Step-by-step explanation:
Adding the same positive numbers will always give you the same answers, right here all your doing is switching the 9 and the 1 ... so 1
Answer: the system has no solution
Step-by-step explanation: for a solution to occur the lines have to cross
Multiplying fractions is just multiplying the numerators together and the denominators together.


To find out which one is bigger, we need a common denominator. The LCM of 7 and 21 is 21, so convert the first fraction into a denominator of 21. 7 goes into 21 three times, multiply this to the numerator and denominator:

Now just compare the numerators to see which one is bigger.

therefore,