What is the ans please?

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3 Answers
Mar 5, 2018

The correct answer is #"option A"#

Explanation:

The inequality is

#1/(4x-3)<=x#

Therefore,

#x-1/(4x-3)>=0#

Putting on the same denominator

#(x(4x-3)-1)/(4x-3)>=0#

#(4x^2-3x-1)/(4x-3)>=0#

The correct answer is #"option A"#

Mar 5, 2018

#0<=(4x^2-3x-1)/(4x-3)# (part a)

Explanation:

given

#color(green)(=> 1/(4x-3)<=x)#

Subtract #color(blue)(1/(4x-3))# from both sides.

#1/(4x-3)-color (red)(1/(4x-3))<=x-color (red)(1/(4x-3))#

#0 <=(x (4x-3)-1)/(4x-3)#

#color (firebrick)(0 <=(4x^2-3x-1)/(4x-3))# or part a

Mar 6, 2018

I will use this online graphing calculator to show that the correct answer is A

Explanation:

First I will show you #color(red)(1/(4x-3)<=x)#

www.desmos.com/calculator

Please observe that it is saying that y is any value that you like but domain of x is #-1/4<=x<3/4# and #x>=1#.

I will save the graph of A for after I have shown that selections B through E are NOT the solutions:

Here is Selection B #color(blue)((4x^2-3x-1)/(4x-3)<=0)#:

www.desmos.com/calculator

Please observe that it is saying that y is any value that you like but domain of x is #-1/4<=x# and #3/4<x<=1#; this clearly disagrees with the graph of the original equation.

Here is Selection C #color(green)(4x^2-3x-1>=0)#

www.desmos.com/calculator

Please observe that it is saying that y is any value that you like but domain of x is #-1/4<=x# and #x>=1#; this clearly disagrees with the graph of the original equation.

Here is Selection D #color(purple)(4x^2-3x-1<=0)#

www.desmos.com/calculator

Please observe that it is saying that y is any value that you like but domain of x is #-1/4<=x<=1#; this clearly disagrees with the graph of the original equation.

I cannot use the inequality function for selection E #color(orange)(4x^2+3x+1<=0)#, because #color(orange)(y = 4x^2+3x+1)# is never less than 0 and, therefore, the domain of the inequality is the null set but I will show you the parabola:

www.desmos.com/calculator

Finally, the correct answer Selection A #(4x^2-3x-1)/(4x-3)>=0#

www.desmos.com/calculator

Please observe that the graph of the original inequality is identical to this graph with the same domain, #-1/4<=x<3/4# and #x>=1#.