It's basic subtraction. you subtract 7 1/8 with 4 4/8 by turning one of the one from the seven to 8/8 and add that to 1/8 so you get 9/8. Then 6 9/8 - 4 4/8 = 2 5/8.
The maximum height is 144 feet.
The maximum height is the y-coordinate of the vertex. To find the vertex, we first use x = -b/2a. For our information, that is x=-64/2(-16) = -64/-32 = 2.
Now we substitute this into the equation:
y = -16(2²) + 64(2) + 80 = -64 + 128 + 80 = 144
Answer:
x = -14
Step-by-step explanation:
x + 6 = 4x/7
7x + 42 = 4x
7x - 4x = -42
3x = -42
x = -42 ÷ 3
x = -14
Aliaa got a mark of 60 in her first 4 tests, so her total mark is 60 x 4 = 240. On her fifth test, she got a mark of 80.
So her average is:
(240+80)/5 = 320/5 = 64
Her avg is 64 (c).