A, B, D are functions.
(First, second, and fourth response)
You can see which is function since for everyone input only has one value. You can also use the vertical line test.
Answer:

Firstly, multiply the number and variable in the perenthesis. Then move the variable on it's own side of the equation. The simplify.
Answer:
where is question ???
Step-by-step explanation:
No, all parallelograms are not squares because squares have to have all 90 degree angles, while parallelograms don't
Answer:
The time taken by object to travel 21 ft is 1 sec
Step-by-step explanation:
The distance travel by falling object given as
d = 5 t + 16 t²
The Distance cover by object to travel = 21 ft
so , from Distance time equation
21 = 5 t + 16 t²
or, 16 t² + 5 t - 21 = 0
Or, 16 t² - 16 t +21 t - 21 = 0
Or, 16 t ( t - 1) + 21 (t - 1) = 0
Or. (t - 1) (16 t + 21) = 0
Or, (t - 1) = 0 And (16 t + 21) = 0
∴ t = 1 And t = (
)
Hence The time taken by object to travel 21 ft is 1 sec Answer