Answer:
Step-by-step explanation:
12+x=16
3x+y=19
4y-10=18
1/2xy=14
12 + x = 16 because x is 4
3x + y is 19 because 3x is 12 and y is 7
4y - 10 is 18 because 4y is 28
1/2 xy is half of 28 or 14
hope this helps and brainliest please