Solve using formula 5(x^2 - 1) = 3x.Give your answer correct to 2 significant figures.
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Question

Solve using formula 5(x^2 - 1) = 3x.Give your answer correct to 2 significant figures. 
@iGreen 
@confluxepic 
@Conqueror 
@AnswerMyQuestions

aaronandyson · Answer

@chosenmatt

aaronandyson · Answer

@sleepyjess

aaronandyson · Answer

@misty1212

misty1212 · Answer

HI!!

misty1212 · Answer

is it $$5(x^2 - 1) = 3x$$\]

aaronandyson · Answer

yes

misty1212 · Answer

start with 
$$5x^2-5=3x$$

misty1212 · Answer

then set it equal to zero and get 
$$5x^2-3x-5=0$$

aaronandyson · Answer

now?

misty1212 · Answer

use the quadratic formula i guess, since this one does not factor

misty1212 · Answer

$$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$with 
$$a=5,b=-3,c=-5$$

misty1212 · Answer

if that is too much work, you can always cheat you are going to need a calculator anyway, since they are asking for the answer as a decimal http://www.wolframalpha.com/input/?i=5x%5E2-3x-5%3D0

aaronandyson · Answer

We are not allowed to use a calculator.

misty1212 · Answer

scroll down to where you see "solutions" and click on "approximate form"

misty1212 · Answer

then you cannot answer it
it asks "Give your answer correct to 2 significant figures. "

misty1212 · Answer

that means you HAVE TO  use a calculator
otherwise you cannot compute the radical

misty1212 · Answer

the answer without a calculator should be 
$$\frac{3\pm\sqrt{109}}{10}$$ but if you want a decimal you need a calculator