20*.4= 8
(20 as the original price, .4 is 40% as a decimal)
20+8
(eight being 40% of 20)
$28 is the new price.
m∠BCD= m∠ACB ÷ 2 = 134.76° ÷ 2 = 67.38°
Ok done. Thank to me :>
Answer:
90 engines must be made to minimize the unit cost.
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 minimum value of the function will happen for 
C(x)=x²-180x+20,482
This means that 
How many engines must be made to minimize the unit cost?
x value of the vertex. So

90 engines must be made to minimize the unit cost.
Answer:
2
Step-by-step explanation:
it literally doubles in size
You have to do 7 x 4 because a square has four sides