Well first you add them together so 72+80=152 and then you devide by two which would make the average grade 76. hope this helps:)
Answer:
(5,6)
Step-by-step explanation:
8X +6Y=4
Y=-3X+9
Substitute the second equation into the first. Every place you see y put -3x+9)
8x +6(-3x+9)=4
Distribute
8x-18x +54 = 4
Combine like terms
-10x +54 = 5
Subtract 54 from each side
-10x +54-54=4-54
-10x = -50
Divide by -10
-10x/-10 = -50/-10
x= 5
Now we need to find y
y = -3x+9
y = -3(5) +9
y = -15+9
y= 6
(5,6)
A is the answer :)
Since we are given z = 8, finding y is simple.
By replacing the z in y + z = 11, we can see that y = 3
After finding these two, x can be found
Can you crop a better photo of the question please