39 is A
40 is D
And that is my answer
Answer:
30 and 9
Step-by-step explanation:
x+y=39 , x-y=21
Solve for x:
x+y=39 , x-y=21
x= 30
Substitute x with 30:
(30)+y=39 , (30)-y=21
Solve for y:
y=9
Answer:
Step-by-step explanation:
To find the inverse function, solve for y:
![x=f(y)\\\\x=4y^4\\\\\dfrac{x}{4}=y^4\\\\\pm\sqrt[4]{\dfrac{x}{4}}=y\\\\f^{-1}(x)=\pm\sqrt[4]{\dfrac{x}{4}}](https://tex.z-dn.net/?f=x%3Df%28y%29%5C%5C%5C%5Cx%3D4y%5E4%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B4%7D%3Dy%5E4%5C%5C%5C%5C%5Cpm%5Csqrt%5B4%5D%7B%5Cdfrac%7Bx%7D%7B4%7D%7D%3Dy%5C%5C%5C%5Cf%5E%7B-1%7D%28x%29%3D%5Cpm%5Csqrt%5B4%5D%7B%5Cdfrac%7Bx%7D%7B4%7D%7D)
f(x) is an even function, so f(-x) = f(x). Then the inverse relation is double-valued: for any given y, there can be either of two x-values that will give that result.
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A function is single-valued. That means any given domain value maps to exactly one range value. The test of this is the "vertical line test." If a vertical line intersects the graph in more than one point, then that x-value maps to more than one y-value.
The horizontal line test is similar. It is used to determine whether a function has an inverse function. If a horizontal line intersects the graph in more than one place, the inverse relation is not a function.
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Since the inverse relation for the given f(x) maps every x to two y-values, it is not a function. You can also tell this by the fact that f(x) is an even function, so does not pass the horizontal line test. When f(x) doesn't pass the horizontal line test, f^-1(x) cannot pass the vertical line test.
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The attached graph shows the inverse relation (called f₁(x)). It also shows a vertical line intersecting that graph in more than one place.
Answer:
3x + 4y = 16 The rule is you can do any valid operation on both sides of an equation and it will still be equal. Subtract 4y.
3x = -4y + 16 Divide by 3.
x = -4y/3 + 16/3 Answer B.