Answer:
85
Step-by-step explanation:
add 4 values, excluding 72 (lowest grade)
total = 339
average = 330/4 = 84.75
84.75 rounding to nearest integer is 85
12 because if you take 2 and add it to 10 you get 12
4x+5y=7
y=3x+9
1) 4x+5(3x+9)=7 2) y=3(-2)+9
y= -6 +9
4x+15x+45=7 y=3
19x+45=7
19x= -38
x= -2
x is -2 and y is 3