Answer:
<em>C. (-2, 7)</em>
Step-by-step explanation:
Put y = 7 to the equation x + y = 5:
x + 7 = 5 <em>subtract 7 from both sides</em>
x = -2
Answer: Total cost would be $53. 24 including tax which is $3.25
The number of protons is the answer