Answer:
The answer to the question provided is:

Step-by-step explanation:
❃Incase you forgot what the point-slope formula is ☟

❃Incase you also forgot, what the slope formula is ☟

➊ First: We are going to be solving for the slope.

➋Second: Plug in.

Answer:
quantity a is halfed
Corrected question;
A quantity a varies inversely as a quantity b, if, when b changes a changes in the inverse ratio. What happens to the quantity a if the quantity b doubles?
Step-by-step explanation:
Analysing the question;
A quantity a varies inversely as a quantity b,
a ∝ 1/b
a = k/b ......1
when b changes a changes in the inverse ratio;
Since the change at the same ratio but inversely, k = 1
So, equation 1 becomes;
a = 1/b
If the quantity b doubles,
ab = 1
a1b1 = a2b2
When b doubles, b2 = 2b1
a1b1 = a2(2b1)
Making a2 the subject of formula;
a2 = a1b1/(2b1)
a2 = a1/2
Therefore, when b doubles, a will be divided by 2, that means a is halfed.
Let L be length and W be width
The perimeter of a rectangle is 2W+2L=36
Thus 2W=36-2L, W=18-L
Area of a rectangle is WL=80
Thus (18-L)(L)=80
18L-L^2=80
L^2-18L+80=0
(L-8)(L-10)
Thus L can either be 8 or 10.
Because WL=80
If L is 8, then W=10
If L is 10, then W=8
So either way, the notebook is 8 by 10
4x^2+25y^2=100

Domain of an ellipse is x ∈ [-a,a] and Range of an ellipse is y ∈ [-b,b].
So, given equation is an Ellipse where Domain is x ∈ [-5,5] and Range is y ∈ [-2,2].
if you meant x^2+9x+20 then it is (x+4)(x+5) you know that because 4+5=9 and 4x5=20 using FOIL