Answer:
y =8.7
Step-by-step explanation:
y + 8.5 = 17.2
Subtract 8.5 from each side
y +8.5 -8.5 = 17.2 -8.5
y =8.7
Answer:
Simplifying 9m + -3 + -7m = 0
Reorder the terms: -3 + 9m + -7m = 0
Combine like terms: 9m + -7m = 2m -3 + 2m = 0 Solving -3 + 2m = 0
Solving for variable 'm'. Move all terms containing m to the left, all other terms to the right.
Add '3' to each side of the equation. -3 + 3 + 2m = 0 + 3 Combine like terms: -3 + 3 = 0 0 + 2m = 0 + 3 2m = 0 + 3 Combine like terms: 0 + 3 = 3 2m = 3
Divide each side by '2'. m = 1.5
Step-by-step explanation:
Hope this helps :)
There are no real roots for a negative number, so -81 has no real roots, if the number is 81 however, then the tow roots are 9
Given:
cos 120°
To find:
The exact value of cos 120° in simplest form with a rational denominator.
Solution:
We have,
It can be written as
![[\because \cos (90^\circ-\theta)=-\sin \theta]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Ccos%20%2890%5E%5Ccirc-%5Ctheta%29%3D-%5Csin%20%5Ctheta%5D)
![[\because \sin 30^\circ=\dfrac{1}{2}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csin%2030%5E%5Ccirc%3D%5Cdfrac%7B1%7D%7B2%7D%5D)
Therefore, the exact value of cos 120° is 
.
Multiply the first equation by -2 to eliminate a variable so it becomes:
-12x+8y=48
4x-8y=-32
Add them together.
-8x=16
x=-2
Plug it in one equation.
6(2)-4y=-24
12-4y=-24
-4y=-12
y=3
Ordered pair is: (-2,3)
