Answer:
All questions are answered in the photo, the answers are correct, but you might have a different method
From the system of equations, we have 3 unknowns and 3 equations. Therefore, it can be solved.
<span>3x - 2y + 2z = 30 (1)
</span><span>-x + 3y - 4z = -33 (2)
</span><span>2x - 4y + 3z = 42 (3)
We can write equation 2 x as a function of y and z and substitute the new equation to the other equations.
</span>x =3y - 4z + 33 (2)
3 (3y - 4z + 3)<span> - 2y + 2z = 30 (1)
</span>2 (3y - 4z + <span>3)</span> - 4y + 3z = 42 (3)
We simplify and solve the equations and we get values,
x = 4
y = -7
z = 2
Answer:
800
Step-by-step explanation:
d=2r=2·400=800
Answer: 460.6 miles South of Chicago
Explanation:
1) <span>The City of New Orleans leaves Union Station in Chicago at 6:00 am and
travels south to New Orleans. The train travels the 930.0 miles to New Orleans at an average speed of 79.0 miles per hour.
Scheme:
→to south ←to north
|----------------------|---------------------|
A x X 930.0 - x B
6:00 am 6:00 am
→ ←
v = 79.0 mi/h v = 81.1 mi/h
=> x = 79.0 mi/h * t
2) at the same time the City of Chicago leaves New Orleans and travels north to Nhicago. The
train travels the 930.0 miles to Chicago at an average speed of 81.1
miles per hour.
930.0 - x = 81.1 mi/h * t
3) How many miles south of chicago do the two trains pass
each other?
Divide the two equations:
930.0 - x 81.1*t
------------- = ----------
x 79*t
t cancels out =>
930.0 - x 81.1
------------- = --------
x 79.0
Solve:
81.1x = 79.0(930.0 - x)
81.1x = 79.0 * 930.0 - 79.0x
81.1x + 79.0x = 73,470
=> 160.1x = 73,470
=> x = 73,470 / 160.1
=> x = 460.6 mi
4) Answer 460.6 miles South of Chicago.
</span>
Answer:
x^2 - 10x + 25 = 17
Step-by-step explanation:
Please use " ^ " to denote exponentation:
x^2 - 10x = -8
x^2 - 10x + 25 = 17
x^2 - 10x + 25 = -8
x^2 - 10x - 25 = -33
Begin with x^2 - 10x = -8. Here's the process for completing the square:
1. Take half of the coefficient of x and square the result:
(1/2)(-10) = -5, and then (-5)^2 = + 25
2. Add this 25 to the first two terms of x^2 - 10x = -8 and also to the constant -8: x^2 - 10x + 25 = -8 + 25, or x^2 - 10x + 25 = 17
3. Match this result to one of the given possible answers. Turns out that the given possible answer matching our result is the first one:
x^2 - 10x + 25 = 17
