8 - ? = -1. the missing number would be 9.
The least-square regression line has a slope of:
m=(nΣxy-ΣyΣx)/(nΣx²-ΣxΣx)
and a y-intercept of:
b=(Σy-mΣx)/n
In this case: n=7, Σxy=4899, Σy=391, Σx=85, Σx²=1153 so
m=(7(4899)-391*85)/(7(1153)-85*85))=1058/846
b=(391*846-85*1058)/(7*846)=34408/846
So the line of best fit is:
y=(1058x+34408)/846 and if we approximated this as your answers see to have done....
y=1.25x+40.67
Hello from MrBillDoesMath!
Answer: SAS = side - angle -side congruence
SSS = side - side - side congruence
Discussion
:
In Plane Geometry, identical triangles are said to be "congruent". There are several ways, depending upon the information you have, to prove 2 triangles are congruent.
In one approach ("SSS") if you can show that 2 triangles have identical side lengths, then the triangles are congruent. (A triangle has 3 sides, hence "SSS" -- 3 S's; 3 sides, get it?)
In another approach ("SAS") if you can show that 2 sides, and the angle included between those sides, in one triangle are identical to the sides and included angle in another triangle, then the triangles are congruent
It's easier to understand this with a picture or diagram than in words. Please review the SSS, SAS picture in your textbook
Regards, MrB
If
is the amount of strontium-90 present in the area in year
, and it decays at a rate of 2.5% per year, then

Let
be the starting amount immediately after the nuclear reactor explodes. Then

or simply

So that after 50 years, the amount of strontium-90 that remains is approximately

or about 28% of the original amount.
We can confirm this another way; recall the exponential decay formula,

where
is measured in years. We're told that 2.5% of the starting amount
decays after 1 year, so that

Then after 50 years, we have

Answer:
The specific weight is 
Step-by-step explanation:
The question in English
A cone has a lateral area of 255 pi cm^2, an apothem of 17 cm and weighs 900 pi g. It calculates the specific weight of the material of which it is composed
step 1
Find the radius of the cone
we know that
The lateral area of a cone is equal to

we have


substitute the values

Simplify


step 2
Find the height of the cone
Applying the Pythagoras Theorem

substitute the values and solve for h




step 3
Find the volume of the cone
The volume of the cone is equal to

substitute the values


step 4
Find the specific weight
Divide the mass by the volume
