Ooh, fun
geometric sequences can be represented as

so the first 3 terms are



the sum is -7/10

and their product is -1/125

from the 2nd equation we can take the cube root of both sides to get

note that a=ar/r and ar²=(ar)r
so now rewrite 1st equation as

subsituting -1/5 for ar

which simplifies to

multiply both sides by 10r
-7r=-2-2r-2r²
add (2r²+2r+2) to both sides
2r²-5r+2=0
solve using quadratic formula
for


so
for 2r²-5r+2=0
a=2
b=-5
c=2




so

or

use them to solve for the value of a


try for r=2 and 1/2

or

test each
for a=-1/10 and r=2
a+ar+ar²=

it works
for a=-2/5 and r=1/2
a+ar+ar²=

it works
both have the same terms but one is simplified
the 3 numbers are

,

, and
Answer:
A.
-19 9 7
[15 -7 6 ]
-2 1 1
Step-by-step explanation:
Answer:2.78×10^2
Step-by-step explanation:
22+52+424-220
=278
In standard form
=2.78×10^2
<span>When given 3 triangle sides, to determine if the triangle is acute, right or obtuse:
</span>1) Square all 3 sides.
2) Sum the squares of the 2 shortest sides.
3) Compare this sum to the square of the 3rd side.
if sum > 3rd side² Acute Triangle
if sum = 3rd side² Right Triangle<span>
if sum < 3rd side² Obtuse Triangle
1) 1,296 2,401 3,600
2) Sum = 3,697
3) </span><span>3,697 is greater than 3,600
Therefore, the triangle is acute.
Source:
http://www.1728.org/triantest.htm
</span>