Y + R + V = 42
but 4 YEARS AGO : (R-4) +(V-4) = Y
Replace Y in the 1st equation by: (R-4) +(V-4)
(R-4) +(V-4) + R + V = 42
2R - 2V - 8 = 42; 2R -2V = 50, or R+V=25
IF R+V =25 AND Y + R +V = 42, then Y + 25 = 42 and Y =17
Answer:
x = -5, and y = -6
Step-by-step explanation:
Suppose that we have two equations:
A = B
and
C = D
combining the equations means that we will do:
First we multiply both whole equations by constants:
k*(A = B) ---> k*A = k*B
j*(C = D) ----> j*C = j*D
And then we "add" them:
k*A + j*C = k*B + j*D
Now we have the equations:
-x - y = 11
4*x - 5*y = 10
We want to add them in a given form that one of the variables cancels, so we can solve it for the other variable.
Then we can take the first equation:
-x - y = 11
and multiply both sides by 4.
4*(-x - y = 11)
Then we get:
4*(-x - y) = 4*11
-4*x - 4*y = 44
Now we have the two equations:
-4*x - 4*y = 44
4*x - 5*y = 10
(here we can think that we multiplied the second equation by 1, then we have k = 4, and j = 1)
If we add them, we get:
(-4*x - 4*y) + (4*x - 5*y) = 10 + 44
-4*x - 4*y + 4*x - 5*y = 54
-9*y = 54
So we combined the equations and now ended with an equation that is really easy to solve for y.
y = 54/-9 = -6
Now that we know the value of y, we can simply replace it in one of the two equations to get the value of x.
-x - y = 11
-x - (-6) = 11
-x + 6 = 11
-x = 11 -6 = 5
-x = 5
x = -5
Then:
x = -5, and y = -6
Answer:

(Assuming you want your answer in radians)
If you want the answer in degrees just multiply your answer in radians by
giving you:
.
We can do this since
(half the circumference of the unit circle is equivalent to 180 degree rotation).
Step-by-step explanation:
is going to output an angle measurement in
.
So we are looking to solve the following equation in that interval:
.
This happens in the second quadrant on the given interval.
The solution to the equation is
.
So we are saying that
implies
since
.
Answer is
.
Answer:
72.22
Step-by-step explanation:
Answer: The cost of 16 pencils and 10 notebooks is $5.84.
Explanation: You can solve this using linear systems:
Let X be the cost per pencil, and let Y be the cost per notebook.
(1) 7x+8y=4.15
(2) 5x+3y=1.77
Choose a variable to eliminate. I’ll eliminate X first as an example. To eliminate a variable, you must have the same coefficient beside the variable for both equations.
Equation 1 now becomes:
(3) 35x+40y=20.75
Equation 2 now becomes:
(4) 35x+21y=12.39
Now that you have 35 as a coefficient for X in both equations, you can subtract the two equations to officially eliminate it!
(3)-(4)
19y=8.36
y=0.44
Now that you have the value of Y, substitute that value into either one of the equations to get X.
Substitute y=0.44 in (1)
7x+8(0.44)=4.15
7x+3.52=4.15
7x=0.63
x=0.09
Therefore, the cost per pencil is $0.09/pencil and the cost per notebook is $0.44/notebook.
Almost done lol...
To find the cost of 16 pencils, multiply 0.09*16. That gives you $1.44, which will be the cost of 16 pencils.
The cost of 10 notebooks is 0.44*10, which gives you $4.40. That’s the cost of 10 notebooks.
To find the total price, add these values together!
1.44+4.40=5.84
Therefore, the cost of 16 pencils and 10 notebooks is $5.84.
Hope that helps シ