Answer:
19cm
Step-by-step explanation:
An equilateral triangle is a triangle where the length of the 3 sides are the same.
the perimeter is the sum of the 3 sides
for example, if the length of the side of the an equilateral triangle is 5, the perimeter is 5 x 3 = 15
let x = unknown length of side
length after increase = x + 5
(x + 5) x 3 = 72
divide both sides of the equation by 3
x + 5 = 24
subtract 5 from both sides of the equation
x = 24 - 5 = 19cm
The dilation factor Sophia is using appears to be
(image coordinate)/(original coordinate) = -9/-3 = 15/5 = 3
Then the problem tells us
(pre-image point)×3 = (3, 1)
so we conclude
(pre-image point) = (3, 1)/3 = (1, 1/3)
Answer:
y = 
Step-by-step explanation:
Let the total numbers are n.
If the average of y numbers is x then we can form an equation
⇒ 
⇒ n = 
--------(1)
Now 30 is added to the set of numbers then average becomes (x - 5)
⇒ 
⇒ (n + 1) = 
⇒ n = - 1 ----- (2)
Now we equate the values of n from equation 1 and 2
= - 1
y(x - 5) = x(y + 30) - x(x - 5) [ By cross multiplication ]
xy - 5y = xy + 30x - x² + 5x
xy - xy - 5y = 35x - x²
-5y = 35x - x²
x² - 35x = 5y
y =
Answer: Choice A
y = -3(x+2)^2 + 10
=================================================
Work Shown:
y = -3x^2-12x-2 is in the form y = ax^2+bx+c with
a = -3
b = -12
c = -2
The x coordinate of the vertex is
h = -b/(2a)
h = -(-12)/(2*(-3))
h = 12/(-6)
h = -2
We'll plug this into the original equation to find the corresponding y coordinate of the vertex.
y = -3x^2-12x-2
y = -3(-2)^2-12(-2)-2
y = 10
So k = 10 is the y coordinate of the vertex.
Overall, the vertex is (h,k) = (-2,10)
Meaning that we go from this general vertex form
y = a(x-h)^2 + k
to this
y = -3(x - (-2))^2 + 10
y = -3(x+2)^2 + 10
