Let the price of the 3rd card be c. Now we can write the equation:
c + (c + 20) + (c + c + 20) = 160 .........(1)
Simplifying the left hand side of equation (1), we get:
4c + 40 = 160 .........(2)
Subtracting 40 from both sides of equation (2) gives:
4c = 120
from which c = $30.
Therefore the price of the second card = 30 + 20 = $50
and the price of the first card = 30 + 50 = $80.
Answer:
x = 15°
Step-by-step explanation:
<em><u>The segment is a diameter, So let us assume the part in which there lies the triangle as a semicircle.</u></em>
=> <em>A triangle inscribed in a semi-circle will always have one of its angle equal to 90</em>
=> <em>So the angle (not 75 and x) is 90 degrees.</em>
<em>=> To find the value of x, we'll subtract rest of the angles from 180 degrees (because the interior angles of a triangle add up to 180°)</em>
<em>So,</em>
=> x = 180-90-75
=> x = 15°
You mean like in a decimal? It'd be 12.5 or 12.50.... Same thing.
Let side be "a" cm. So another side is (30-2a)/2=15-a
S=ab=a(15-a)=15a-a^2 - parabola
maximum when a = -15/-2=7.5 cm
When a=7.5 all sides are 7.5 cm
So it's a square. S=a*a=7.5*7.5=56.25 cm^2 - max
There is no global minimun for S.(look at the graphic)
