3a + b = 54...when b = 9
3a + 9 = 54
3a = 54 - 9
3a = 45
a = 45/3
a = 15 <===
Answer:
C is the most reasonable answer because to add the system of equations together, you must make sure that one of the terms (whether it be the x or y value) can cancel out.
Step-by-step explanation:
first, you would rearrange the equation so that like terms were next to each other.
7y - 5y - x2 + 2x2 +3x - 17x
then you would reduce the equation based on like terms
2y + x2 - 14x
then simply rearrange the equation to get the answer, which is <u>B</u>