Which rational expression has a value of 0 when x = 2 ? A) 7x -5/x2 + 10 B) -3x +6/8x-9 C) -5x + 8 / x-2

Mathematics

2 answers:

shepuryov [24]3 years ago

7 0

answer for this question is (b) - 3 x + 6 x /8x- 9

nekit [7.7K]3 years ago

3 0

<h2>Answer:</h2>

Option: B is the correct answer.

B) $\dfrac{-3x+6}{8x-9}$

<h2>Step-by-step explanation:</h2>

We are asked to find the expression which gives the value zero when we substitute x=2.

Hence, we will check each of the options by putting x=2.

$\dfrac{7x-5}{x^2}$

when x=2 we have:

$\dfrac{7\times 2-5}{2^2}\\\\=\dfrac{14-5}{4}\\\\=\dfrac{9}{4}\neq 0$

Hence, option: A is incorrect.

$\dfrac{-3x+6}{8x-9}$

when x=2 we have:

$=\dfrac{-3\times 2+6}{8\times 2-9}\\\\=\dfrac{-6+6}{16-9}\\\\=\dfrac{0}{7}\\\\=0$

Hence, option: B is correct.

$\dfrac{-5x+8}{x-2}$

when we substitute x=2

we observe that the denominator is zero but the numerator is non-zero.

Hence, x=2 is a excluded point of the rational expression.

Hence, option: C is incorrect.

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Write a formula for function f in terms of function g.

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so hmm if you notice, your f(x) there, looks just like g(x), but is "shifted horizontally" by about 9 units to the right

that simply means, based on that template above, that C/B = -9, and we can simply make B = 1 and C = -9, and we get C/B = -9/1 which is -9

thus $\bf \begin{array}{llcll}
f(x)=g(&1x&-9)\\
&\uparrow &\uparrow \\
&B&C
\end{array}\iff f(x)=g(x-9)$