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29 votes
29 votes
Solve for x:

8x^2−3=2

Please provide a step-by-step answer.

User Giovanni Cerretani
by
2.5k points

2 Answers

17 votes
17 votes

Answer:


x = \boxed{ (√(10))/(4) , - (√(10))/(4) }

Explanation:

We can solve this question by using the method of finding the square root.

The given equation is:


8x ^ { 2 } -3=2

Add 3 to both the sides of the equation.


8x^(2)=2+3

Now, add 2 & 3 to get 5.


8x^(2)=5

Dividing both the sides of the equation by 8, we get...


x^(2)=(5)/(8)

Now, take the square root of both the sides of the equation...


x =\sqrt{ ( 5 )/( 8 ) } \\x = (√(5))/(√(8)) \\

Rationalize the denominator.


x = (√(5))/(2√(2)) \\x = (√(5)√(2))/(2\left(√(2)\right)^(2)) \\x = (√(5)√(2))/(2* 2) \\x = (√(10))/(2* 2) \\x = \boxed{ (√(10))/(4) , - (√(10))/(4) }


\rule{200}{3}

  • The value of x =
    \boxed{ (√(10))/(4) , - (√(10))/(4) }


\rule{200}{3}

Hope this helps!

User Mike Brind
by
3.1k points
18 votes
18 votes

Answer:


\rf x=(√(10))/(4),\:x=-(√(10))/(4)

step wise explanation:


  • \rf 8x^2 - 3=2

change sides:


  • \rf 8x^2 =2+3

simplify


  • \sf 8x^2 = 5

change sides:


  • \sf x^2 = (5)/(8)

changing square to square root:


  • x = \pm \sqrt{(5)/(8) }

normal answer:


  • \rf \sqrt{(5)/(8) } \ \ or -\sqrt{(5)/(8) }

apply radical rule of


  • \rf (√(5) )/(√(8) ) } \ \ or \rf -(√(5) )/(√(8) ) }

  • \sf (√(5))/(2√(2)) \ \ or \ \ \sf -(√(5))/(2√(2))

rationalise:


  • (√(5)√(2))/(2√(2)√(2)) \ \ or \ - (√(5)√(2))/(2√(2)√(2))

final answer, simplified:


  • \rf x=(√(10))/(4),\:x=-(√(10))/(4)
User Pursuit
by
2.7k points