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r(x)=3x^2-6x+5 find the following r=(-.5) please help

 

I am trying too use PEMDAS but keep getting various answers 

 May 22, 2019

Best Answer 

 #1
avatar+247 
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This can be rewritten as \(r(-.5)=3(-.5)^2-6(-.5) +5\)

The P in pemdas is for parentheses. There are no parentheses. Next is exponents, so you would find \((-.5)^2\). A negative times a negative is positive so that is .25. 

\(r(-.5)=3(.25)-6(-.5)+5\)

There are two things that need to be multiplied next and no division.

3(.25)=.75 and 6(-.5)= -3

\(r(-.5)=.75-(-3)+5\)

Now do adition and subtraction from left to right. Subrtacting the negative three canceles out so the 3 is added.

\(.75+3+5=\boxed{8.75}\)

 

 

(Be careful when using PEMDAS. If there is multiplication and devision you wouldn't do all the multiplication then all the devision you would do the computations from left to right. The same goes for adition and subtraction.)

 

(You used function notation wrong. You would write it as r(-.5) or x=-.5)

 May 22, 2019
 #1
avatar+247 
0
Best Answer

This can be rewritten as \(r(-.5)=3(-.5)^2-6(-.5) +5\)

The P in pemdas is for parentheses. There are no parentheses. Next is exponents, so you would find \((-.5)^2\). A negative times a negative is positive so that is .25. 

\(r(-.5)=3(.25)-6(-.5)+5\)

There are two things that need to be multiplied next and no division.

3(.25)=.75 and 6(-.5)= -3

\(r(-.5)=.75-(-3)+5\)

Now do adition and subtraction from left to right. Subrtacting the negative three canceles out so the 3 is added.

\(.75+3+5=\boxed{8.75}\)

 

 

(Be careful when using PEMDAS. If there is multiplication and devision you wouldn't do all the multiplication then all the devision you would do the computations from left to right. The same goes for adition and subtraction.)

 

(You used function notation wrong. You would write it as r(-.5) or x=-.5)

power27 May 22, 2019

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