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:
x= 9
Step-by-step explanation:
good luck
Answer:
It simplifies to 2x + 2.
Step-by-step explanation:
Let the number be x, then the expression is
x + 5 + (x - 3)
= x + 5 + x - 3
= x + x + 5 - 3
= 2x + 2.
I don't get the question u r answering
Answer: cos²(θ) + sin(θ)sin(e)
<u>Step-by-step explanation:</u>
sin (90° - θ)cos(Ф) - sin(180° + θ) sin(e)
Note the following identities:
sin (90° - θ) = cos(x)
sin (180° + θ) = -sin(x)
Substitute those identities into the expression:
cos(x)cos(x) - -sin(x)sin(e)
= cos²(x) + sin(x)sin(e)