Answer:
k = 3
Step-by-step explanation:
-12 = 3 - 2k - 3k
-12 = 3 - 5k
5k = 15
k = 3
Answer:
C
Step-by-step explanation:
Answer:
We have to prove
sin(α+β)-sin(α-β)=2 cos α sin β
We will take the left hand side to prove it equal to right hand side
So,
=sin(α+β)-sin(α-β) Eqn 1
We will use the following identities:
sin(α+β)=sin α cos β+cos α sin β
and
sin(α-β)=sin α cos β-cos α sin β
Putting the identities in eqn 1
=sin(α+β)-sin(α-β)
=[ sin α cos β+cos α sin β ]-[sin α cos β-cos α sin β ]
=sin α cos β+cos α sin β- sinα cos β+cos α sin β
sinα cosβ will be cancelled.
=cos α sin β+ cos α sin β
=2 cos α sin β
Hence,
sin(α+β)-sin(α-β)=2 cos α sin β
For the sake of showing work I will replace the empty space with an x like so...
To find out what x is you must cross multiply (aka butterfly)
***Image of this step is attached below
9*x = 10*90
9x = 900
Next divide 9 to both sides to finish isolating x. Since 9 is being multiplied by x, division (the opposite of multiplication) will cancel 9 out (in this case it will make 9 one) from the left side and bring it over to the right side.
9x ÷ 9 = 900 ÷ 9
1x = 100
x = 100
To make these fractions equivalent the empty spot must be 100
Hope this helped!
~Just a girl in love with Shawn Mendes
Factor the following:
10 y^2 - 35 y + 30
Factor 5 out of 10 y^2 - 35 y + 30:
5 (2 y^2 - 7 y + 6)
Factor the quadratic 2 y^2 - 7 y + 6.
The coefficient of y^2 is 2 and the constant term is 6.
The product of 2 and 6 is 12.
The factors of 12 which sum to -7 are -3 and -4. So 2 y^2 - 7 y + 6 = 2 y^2 - 4 y - 3 y + 6 = y (2 y - 3) - 2 (2 y - 3):
5 y (2 y - 3) - 2 (2 y - 3)
Factor 2 y - 3 from y (2 y - 3) - 2 (2 y - 3):
Answer: 5 (2 y - 3) (y - 2)
