Two-dimensional figures are one category and polygons are a separate category that falls under two-dimensional because 2D(two dimensional) figures are figures that do not have a volume so they are flat. Polygons are flat 2D shapes that have straight lines and all lines are closed, meaning that they don't have any disconnected lines. Polygons are a subcategory of 2D figures because they carry all traits of 2D figures but also have special ones of their own. Examples of polygons are squares, rectangles, and triangles. Examples of nonpolygons but still are 2D figures are circles, ovals, and any other flat shape.
Answer:
Let x = the number
"Fifteen more than" means addition
"Three times a number" is multiplication
"three less than" is subtraction, as is the term difference
Putting it all together, we have
7 - (15 + 3x) = (9 - 5x) - 3
-8 + 3x = 6 - 5x
-8 = 6 - 8x
-14 = -8x
14/8 = 7/4 = x
Step-by-step explanation:
the answer is <em>D</em>
<em>Hopefully</em><em> </em><em>this</em><em> </em><em>helps</em><em> </em><em>you</em><em>!</em>
The foci of the hyperbola with equation 5y^2-4x^2=20 will be given as follows:
divide each term by 20
(5y^2)/20-(4x^2)/20=20/20
simplifying gives us:
y^2/4-x^2/5=1
This follows the standard form of the hyperbola
(y-k)²/a²-(x-h)²/b²=1
thus
a=2, b=√5 , k=0, h=0
Next we find c, the distance from the center to a focus.
√(a²+b²)
=√(2²+(√5)²)
=√(4+5)
=√9
=3
the focus of the hyperbola is found using formula:
(h.h+k)
substituting our values we get:
(0,3)
The second focus of the hyperbola can be found by subtracting c from k
(h,k-c)
substituting our values we obtain:
(0,-3)
Thus we have two foci
(0,3) and (0,-3)
