2x + 3y = 45
x + y = 10......y = 10 - x
2x + 3(10 - x) = 45
2x + 30 - 3x = 45
-x + 30 = 45
-x = 45 - 30
-x = 15
x = -15 <====
and y = 25
Answer:
C
Step-by-step explanation:
I would say C because,
Even + Even = Even.
Odd + Odd = Odd.
So simply, you can't have an even number if you add it to a odd.
Even + Odd = Odd
Answer: 
Step-by-step explanation:
You know that the given function is:

You know that you must evaluate this function for
.
Then, to evaluate the function for
, you need to substitute this value into the given function and simplify it.
Therefore, you get:

So, the answer is: 
Answer: (4, -9)
<u>Step-by-step explanation:</u>
Use elimination method. Manipulate one (or both) equations to eliminate one of the variables and solve for the remaining variable. <em>I will be eliminating y</em>
6x + y = 15 → 2(6x + y = 15) → 12x + 2y = 30
-7x - 2y = -10 → 1(-7x + 2y = -10) → <u> -7x - 2y = -10</u>
5x = 20
x = 4
Next, replace "x" with "4" into either equation and solve for y.
6(4) + y = 15
24 + y = 15
y = -9
<u>Check:</u>
Plug in x = 4 and y = -9 into the other equation to verify it makes a true statement.
-7x - 2y = -10
-7(4) - 2(-9) = -10
-28 - -18 = -10
-28 + 18 = -10
-10 = -10 
Work is force times distance. Note that the only work done here is in the direction opposed to gravity, or if you prefer the change in height times the weight...
W=3sin20(8*9.8)
W≈80.44 J