Answer:
-16d+24
Step-by-step explanation:
=> -8(2d-3)
Expand the brackets and use distributive property.
=> (-8 × 2d)+(-8 × -3)
Multiply
=> (-16d) + (24)
=> -16d+24
Step-by-step explanation:
7-3cosx=9sin²x
[sin²x=1-cos²x]
=>
7-3cosx=9-9cos²x
=>
9cos²x-3cosx-2=0
=>
let cosx=t
9t²-3t-2
by quadratic formula,
t=(3±9)/2·9
=> t=2/3 or t=-1/3
thus,
x=acos(2/3) or x=π- acos(1/3)
Answer:
x=4
y=4√5
Step-by-step explanation:
Set up 3 right triangles and mark their respective angles. The largest will have sides (in typical a,b,c[hypotenuse] order) y, z, and 10. The middle 8, x, and y. The smallest x, 2, and z.
Then since they are all similar triangles, using the midde and smaller triangles, set up the proportionin which both A sides when divided are equal to the B sides.
So 8/x = x/2
Cross multiply and get 16=x^2.
The square root of 16 is 4, so x is 4.
Then using the larger and middle triangles, do the same for the A and C sides.
So y/8 = 10/y.
Cross multiply and get 80=y^2.
Find the square root of it, which since it doesn't have a perfect square, you use a calculator or the whatever theorem and get √4*4*5 or simply 4√5.
So x = 4 and y = 4√5
Since two people take both courses, we can subtract two from 7, 8, and 21, giving us 5, 6, and 19.
Add 5 and 6 together to get 11. Since eleven students are in those two groups, we can answer this. The answer will be 11/19.
Answer:x>4;r-1(x)=4-(root of (11/x))
Step-by-step explanation:
Edgenuity 2020