(3 cos x-4 sin x)+(3sin x+4 cos x)=5
(3cos x+4cos x)+(-4sin x+3 sin x)=5
7 cos x-sin x=5
7cos x=5+sin x
(7 cos x)²=(5+sinx)²
49 cos²x=25+10 sinx+sin²x
49(1-sin²x)=25+10 sinx+sin²x
49-49sin²x=25+10sinx+sin²x
50 sin² x+10sinx-24=0
Sin x=[-10⁺₋√(100+4800)]/100=(-10⁺₋70)/100
We have two possible solutions:
sinx =(-10-70)/100=-0.8
x=sin⁻¹ (-0.8)=-53.13º (360º-53.13º=306.87)
sinx=(-10+70)/100=0.6
x=sin⁻¹ 0.6=36.87º
The solutions when 0≤x≤360º are: 36.87º and 306.87º.
7/4 because you times 4 and 1.then add 3 and you get 7 so 7/4
Answer: 2 buses and 4 vans would be needed
Step-by-step explanation:
Let x represent the number of buses that would be needed.
Let y represent the number of vans that would be needed.
There will be six drivers, and two different types of vehicles. This means that
x + y = 6
142 students are going on a field trip. A bus can hold 51 people while a van can hold 10. This means that
51x + 10y = 142 - - - - - - - - - - - 1
Substituting x = 6 - y into equation 1, it becomes
51(6 - y) + 10y = 142
306 - 51y + 10y = 142
- 51y + 10y = 142 - 306
- 41y = - 164
y = - 164/ - 41
y = 4
x = 6 - y = 6 - 4
x = 2
Answer:
18.3
18.3 only has three significant figures while the other numbers have more
Answer:
x>9
Step-by-step explanation:
-4x + 15 < -21
Subtract 15 from each side
-4x + 15-15 < -21-15
-4x < -36
Divide each side by -4, remembering to flip the inequality
-4x/-4> -36/-4
x >9
