Answer:
Part A:




Part B:


and 
Step-by-step explanation:
Part A:
The inicial concentration of the lemonade is 50%, and the volume is 4 quarts, and we will add x quarts of a lemonade with a concentration of 100%, so the total volume will be y, and the concentration will be 0.7, so we have that:


Using the value of y from the first equation in the second one, we have:





Part B:
If he shoots a total of ten targets, we can write the equation:

Each stationary target is 2 points, and each moving target is 3 points, so if the total points is 23, we have:

If we subtract the second equation by two times the first one, we have:



⇒ 
You just need to plug the values: you have to multiply
and
, and then divide the result by -3.
So, if
, we have 
Which means that 
And the final answer is 
Answer:
y = 0
x = -4
( x, y ) = ( -4 , 0 )
Step-by-step explanation:
y = 5x + 20
y = -2x - 8
Substitute
5x + 20 = -2x - 8
Add 8 on both sides
5x + 20 + 8 = -2x - 8 + 8
5x + 28 = -2x
Subtract 5x on both sides
5x - 5x + 28 = -2x - 5x
28 = -7x
Divide by -7 on both sides
28/-7 = -7x/-7
-4 = x
Now that you have x, you can substitute it in one of the equations that was given to find the value of y.
y = 5x + 20
y = 5(-4) + 20
y = -20 + 20
y = 0
Or....
y = -2x - 8
y = -2(-4) - 8
y = 8 - 8
y = 0
They will both be 0 no matter what
Point form = ( -4, 0 )
Hope this helped
Second moment of area about an axis along any diameter in the plane of the cross section (i.e. x-x, y-y) is each equal to (1/4)pi r^4.
The second moment of area about the zz-axis (along the axis of the cylinder) is the sum of the two, namely (1/2)pi r^4.
The derivation is by integration of the following:
int int y^2 dA
over the area of the cross section, and can be found in any book on mechanics of materials.
Answer:
x > -2
Step-by-step explanation:
-3x + 12 < 18
Subtract the 12 from both sides and you'll get:
-3x < 6
Divide by -3
x > -2
You flip the sign when you mulitply by a negative number
Hopefully this helps, sorry if it doesn't