Answer:
x = 20
Step-by-step explanation:
Since the triangles are similar then the ratios of corresponding sides are equal, that is
= 
( cross- multiply )
9x = 180 ( divide both sides by 9 )
x = 20
Answer: Assume c = 0
Step-by-step explanation:
Step-by-step explanation:
Assume c = 0
Using the formula for the x-coordinate of the vertex, b can be calculated in terms of a:
B can then be substituted into the quadratic equation, along with the coordinates of the vertex, to solve a:
AND
Substituting into the quadratic equation:
Because a is negative, the parabola opens up.
Answer:
That is quite simple,7 is the best choice
200 * 33/40 = 165 owns phones
165 * 10/11 = 150 owns phones and MP3 player
Therefore 3/4 owns both and
165 owns only phones
