B is incorrect. I may be using the wrong word, but addition and multiplication are commutative, so the numbers can be added in any order or multiplied in any order and you’d still get the same sum or product. However, you can’t do this with subtraction or division as the difference or quotient will be different.
Answer:
280 miles
Step-by-step explanation:
Divide 420 by 12 to find the unit rate of miles per gallon.
You get 35 miles per gallon
To find how many miles he can travel for 8 gallons, multiply 35 by 8.
You get 280 miles.
Answer:
The bird will be at a ground distance of 10.04 units away.
Step-by-step explanation:
Vertex of a quadratic function:
Suppose we have a quadratic function in the following format:

It's vertex is the point 
In which


Where

If a<0, the vertex is a maximum point, that is, the maximum value happens at
, and it's value is
.
Equation for the height:
The height of the bird after x seconds is given by:

Which is a quadratic equation with
.
When the bird is at its highest?
Quadratic equation with
, and thus, at the vertex. The ground distance is the x-value of the vertex. Thus

The bird will be at a ground distance of 10.04 units away.