Answer:
see explanation
Step-by-step explanation:
(3)
Given cosΘ = - 
Then by Pythagoras' theorem the third side is 3 ( 3,4, 5 triangle )
Since Θ in second quadrant then sinΘ > 0
sinΘ = 
Using the trigonometric identity
sin2Θ = 2sinΘcosΘ, then
sin2Θ = 2 × × - = - 
(4)
Using the trigonometric identity
cos(x - y) = cosxcosy + sinxsiny
note cos15° = cos(45 - 30)°
cos(45 - 30) = cos45cos30 + sin45sin30
= ( 
× 
) + ( × 
)
= 
The answer it’s a. Pretty sure if not sorry
9514 1404 393
Answer:
Step-by-step explanation:
Adding the same number to both sides of the equation is an acceptable move. The addition property of equality tells Grace that the value of the variable will remain unchanged by such a move.
Her new equation would be ...
2x +20 +10 = 15 +10
2x +30 = 25 . . . . the result of Grace's move
_____
<em>Additional comment</em>
There may be very good reasons why Grace would want to do that. If solving the equation is Grace's intent, that move would be counterproductive. For the purpose of solving the equation, it would be more productive to either subtract 20 from both sides, or divide both sides by 2. These steps would give, respectively, ...
2x = -5
x +10 = 7.5
Answer:
x= -19
y= -14
Step-by-step explanation:
Substitution.
It tells you what y is already. You substitute that into the second equation and then solve. Then you use that answer and substitute it back into the first equation's x, and then you'll get your full answer.
Hope this helps <3
Answer:
30% Probability
Step-by-step explanation: 3/10=0.3
