Answer:
A.
Step-by-step explanation:
Answer:
12r^2 +r -7
Step-by-step explanation:
9r^2 +4r -7 +3r^2 -3r
Combine like terms
9r^2 +3r^2 +4r -3r -7
12r^2 +r -7
Answer:
60%
Step-by-step explanation:
20,000
we can move the decimal place one to the left to find 10 percent
2,000
multiply 10 x 2 to find twenty percent or 4,000
we add this to the original total. 24,000
then add the 8,000
32,000
we know find one percent of the original total
200
and find the difference between the two totals
32000-20000 = 12,000
12000 divided by 200 which is 6
multiply six by ten to get
60 percent
Answer:
Step-by-step explanation:
![\cos(2x) = \cos^2 x-\sin^2 x = 1-2\sin^2 x \\ \\ \cos(x) = 1-2\sin^2 (\frac{x}{2}) \\ \\ \Rightarrow \sin^2 (\frac{x}{2}) = \dfrac{1-\cos(x)}{2}\\ \\ \sin(\frac{x}{2}) = \pm \sqrt{\dfrac{1-\cos(x)}{2}},\quad x\in [\frac{3\pi }{2},\pi] \Rightarrow \frac{x}{2}\in [\frac{3\pi}{4},\frac{\pi}{2}]\\ \\ \Rightarrow \sin(\frac{x}{2}) > 0 \Rightarrow \sin(\frac{x}{2}) = \sqrt{\dfrac{1-(-\frac{3}{5})}{2}} \Rightarrow \sin(\frac{x}{2}) = \sqrt{\dfrac{8}{10}}=\dfrac{2\sqrt 2}{\sqrt{10}} = \\ \\ =\dfrac{2\sqrt 5}{5}](https://tex.z-dn.net/?f=%5Ccos%282x%29%20%3D%20%5Ccos%5E2%20x-%5Csin%5E2%20x%20%3D%201-2%5Csin%5E2%20x%20%5C%5C%20%5C%5C%20%5Ccos%28x%29%20%3D%201-2%5Csin%5E2%20%28%5Cfrac%7Bx%7D%7B2%7D%29%20%5C%5C%20%5C%5C%20%5CRightarrow%20%5Csin%5E2%20%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Cdfrac%7B1-%5Ccos%28x%29%7D%7B2%7D%5C%5C%20%5C%5C%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Cpm%20%5Csqrt%7B%5Cdfrac%7B1-%5Ccos%28x%29%7D%7B2%7D%7D%2C%5Cquad%20x%5Cin%20%5B%5Cfrac%7B3%5Cpi%20%7D%7B2%7D%2C%5Cpi%5D%20%5CRightarrow%20%5Cfrac%7Bx%7D%7B2%7D%5Cin%20%5B%5Cfrac%7B3%5Cpi%7D%7B4%7D%2C%5Cfrac%7B%5Cpi%7D%7B2%7D%5D%5C%5C%20%5C%5C%20%5CRightarrow%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3E%200%20%5CRightarrow%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Csqrt%7B%5Cdfrac%7B1-%28-%5Cfrac%7B3%7D%7B5%7D%29%7D%7B2%7D%7D%20%5CRightarrow%20%5Csin%28%5Cfrac%7Bx%7D%7B2%7D%29%20%3D%20%5Csqrt%7B%5Cdfrac%7B8%7D%7B10%7D%7D%3D%5Cdfrac%7B2%5Csqrt%202%7D%7B%5Csqrt%7B10%7D%7D%20%3D%20%5C%5C%20%5C%5C%20%3D%5Cdfrac%7B2%5Csqrt%205%7D%7B5%7D)
Answer:
a = -3
Step-by-step explanation:
35 = -7a + 14
-14 + 35 = -7a + 14 - 14
21 = -7a
21/-7 = -7a/-7
-3 = a
a = -3
