Have you learned matrices yet? I'm going to use that to solve these, please refer to the photos.
I solved the system by using a matrix calculation. The work always needs to be shown and you do that by setting up the matrix like in the first photo and also writing out all your equations. In a TI calculator, to do this you press 2ND-X^-1,GO TO EDIT - [A] - 3×4- now enter the coefficient of the system of equations variables. NOW 2ND MODE- 2ND-X^-1 -GO TO MATH- ALPHA APPS
Now, if you don't know this you may be confuse so after rref([A]) was enter a matrix came up with [1 0 0 -21] in the top row this means x equal -21. So, the next row is y and it came out as [0 1 0 46] so y equals 46 and I'm going to let you figure out what z is by looking at the matrix.
SO... X=-21 Y=46 and Z=-10
Let's Test it
ANSWER
(C) d=1
EXPLANATION
The given equation is

Factor the first fraction to get,

Multiply through by (d+2)(d-4)

Expand:




divide both sides by -2

Answer:
0.21 and 0.22
Step-by-step explanation:
Answer:
16.5 hours
Step-by-step explanation:
Here is the explanation. As Hye drinks 4/3 gallons of water in 11/2 hours, we have a constant rate. There are 12 thirds in 4, so we are trying to find how long it takes Hye to drink 12/3 gallon. In this case, 4/3x3=12/3, so we multiply 11/2 by 3 as well, which gives us 33/2 hours. 33/2 in decimal form is 16.5 hours. Hope it helps!
Answer:
The unknown angle =
27°
Note :
SOH = Sin angle = Opposite/hypotenuse
CAH = Cos angle = Adjacent/Hypotenuse
TOA = Tan angle = Opposite/Adjacent