Answer:
UV=142
Step-by-step explanation:
21x-13=10x+31
+13 +13
21x=10x+44
-10x=-10x
11x=44
÷11 ÷11
x=4
now substitute 4 in place of x (only have to solve one)
21(4)-13= 71
now multiply your answer by 2
71×2=142
Put them into y=mx+b
y=1/3x -1
y=2/3x-4
Graph them. Where they touch is your answer. No touch? No solution. Same line? Infinite solutions.
Second set: Same thing.
Solution to first set is (9,2)
Answer:
c^2=a^2+b^2
c^2=6^2+8^2
c^2=36+64
c=10
but still do not understand why peoples are asking that basic
Note that f(x) as given is <em>not</em> invertible. By definition of inverse function,
which is a cubic polynomial in 
with three distinct roots, so we could have three possible inverses, each valid over a subset of the domain of f(x).
Choose one of these inverses by restricting the domain of f(x) accordingly. Since a polynomial is monotonic between its extrema, we can determine where f(x) has its critical/turning points, then split the real line at these points.
f'(x) = 3x² - 1 = 0 ⇒ x = ±1/√3
So, we have three subsets over which f(x) can be considered invertible.
• (-∞, -1/√3)
• (-1/√3, 1/√3)
• (1/√3, ∞)
By the inverse function theorem,
where f(a) = b.
Solve f(x) = 2 for x :
x³ - x + 2 = 2
x³ - x = 0
x (x² - 1) = 0
x (x - 1) (x + 1) = 0
x = 0 or x = 1 or x = -1
Then 
can be one of
• 1/f'(-1) = 1/2, if we restrict to (-∞, -1/√3);
• 1/f'(0) = -1, if we restrict to (-1/√3, 1/√3); or
• 1/f'(1) = 1/2, if we restrict to (1/√3, ∞)
The angles of ∠EFG and ∠GFH are 71° and 109°
<h3>What are linear pair angles?</h3>
Linear pair of angles are formed when two lines intersect each other at a single point.
In other words, a linear pair of angles is a pair of adjacent angles formed when two lines intersect each other.
Linear pair angles are supplementary. This means the sum of a linear pair angles is 180 degrees.
Therefore,
∠EFG + ∠GFH = 180
Therefore,
∠EFG = 4n + 15
∠GFH = 5n + 39
hence,
4n + 15 + 5n + 39 = 180
9n + 54 = 180
9n = 180 - 54
9n = 126
n = 126 / 9
n = 14
Hence,
∠EFG = 4n + 15 = 4(14) + 15 = 71°
∠GFH = 5n + 39 = 5(14) + 39 = 109°
learn more on linear pair angles here: brainly.com/question/28264317
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