Answer:
Step-by-step explanation:
![1-2\sin^2x=\sin x\\\\\text{substitute}\ t=\sin x,\ t\in[-1,\ 1]\\\\1-2t^2=t\qquad\text{subtract t from both sides}\\\\-2t^2-t+1=0\qquad\text{change the signs}\\\\2t^2+t-1=0\\\\2t^2+2t-t-1=0\\\\2t(t+1)-1(t+1)=0\\\\(t+1)(2t-1)=0\iff t+1=0\ \vee\ 2t-1=0\\\\t+1=0\qquad\text{subtract 1 from both sides}\\\boxed{t=-1}\\\\2t-1=0\qquad\text{add 1 to both sides}\\2t=1\qquad\text{divide both sides by 2}\\\boxed{t=\dfrac{1}{2}}](https://tex.z-dn.net/?f=1-2%5Csin%5E2x%3D%5Csin%20x%5C%5C%5C%5C%5Ctext%7Bsubstitute%7D%5C%20t%3D%5Csin%20x%2C%5C%20t%5Cin%5B-1%2C%5C%201%5D%5C%5C%5C%5C1-2t%5E2%3Dt%5Cqquad%5Ctext%7Bsubtract%20t%20from%20both%20sides%7D%5C%5C%5C%5C-2t%5E2-t%2B1%3D0%5Cqquad%5Ctext%7Bchange%20the%20signs%7D%5C%5C%5C%5C2t%5E2%2Bt-1%3D0%5C%5C%5C%5C2t%5E2%2B2t-t-1%3D0%5C%5C%5C%5C2t%28t%2B1%29-1%28t%2B1%29%3D0%5C%5C%5C%5C%28t%2B1%29%282t-1%29%3D0%5Ciff%20t%2B1%3D0%5C%20%5Cvee%5C%202t-1%3D0%5C%5C%5C%5Ct%2B1%3D0%5Cqquad%5Ctext%7Bsubtract%201%20from%20both%20sides%7D%5C%5C%5Cboxed%7Bt%3D-1%7D%5C%5C%5C%5C2t-1%3D0%5Cqquad%5Ctext%7Badd%201%20to%20both%20sides%7D%5C%5C2t%3D1%5Cqquad%5Ctext%7Bdivide%20both%20sides%20by%202%7D%5C%5C%5Cboxed%7Bt%3D%5Cdfrac%7B1%7D%7B2%7D%7D)
Answer:
70
Step-by-step explanation:
60/40Ⅹ50=70
I hope this helps
Answer:
B and C work. A and D do not.
Step-by-step explanation:
This is one of those questions that you have to go through each answer to see what the results are. You don't have to go far to eliminate A and D so let's do that first.
A]
5n + 6
Let n = 1
5(1) + 6
5 + 6= 11
However there is trouble beginning with n = 2
5*2 + 6
10 + 6
16 All you need is one wrong answer and the choice is toast. So A won't work.
================
Try D
6(n - 1)+ 5
n=0
6*(-1) + 5
-6 + 5
- 1
And D has been eliminated with just 1 attempt. n= 2 or n = 1 would be even worse. D is not one of the answers.
=============
B
Let n = 1
6(1) + 5
6 + 5
11 The first term works.
n = 2
6*(2) + 5
12 + 5
17 and n = 2 works as well. Just in case it is hard to believe, let's try n = 3 because so far, everything is fine.
n = 3
6*(3) + 5
18 + 5
23 And this also works. I'll let you deal with n = 4
========
C
n = 0
6(0 + 1) + 5
6*1 + 5
6 + 5
11
n = 1
6(1 + 1) + 5
6*2 + 5
12 + 5
17 which works.
So C is an answer.
Answer:
trinomial
Step-by-step explanation:
