Use the Quadratic Formula to solve: 10x^2-16x=5

[flora33]

I am pretty sure how to do this, all the way up to the last few steps:

10x^2-16x=5
10x^2-16x-5=0
Quadratic Formula: x=-b+/-SQRT[b^2-4ac]/2a
x=--16+/-SQRT[-16^2-4(10)(-5)]/2(10)
x=16+/-SQRT[256+200]/20
x=16+/-SQRT[456]/20
I'm not sure if I'm simplifying the square root of 456 correctly:
Answer: x=16 +/- 2 SQRT[114]/20

Did I miss anything? Do I need to do more to this equation?

Thanks!
Flora

 

[Mrspi]

I am pretty sure how to do this, all the way up to the last few steps:

10x^2-16x=5
10x^2-16x-5=0
Quadratic Formula: x=-b+/-SQRT[b^2-4ac]/2a
x=--16+/-SQRT[-16^2-4(10)(-5)]/2(10)
x=16+/-SQRT[256+200]/20
x=16+/-SQRT[456]/20
I'm not sure if I'm simplifying the square root of 456 correctly:
Answer: x=16 +/- 2 SQRT[114]/20

Did I miss anything? Do I need to do more to this equation?

Thanks!
Flora

The only additional thing you should do is reduce the fraction. Factor a 2 out of both terms of the numerator:

x = 2*[8 +/- sqrt(114)] / 20

Then divide numerator and denominator by 2.

 

[masters]

You can factor a 2 from your numerator:

x=(2(8±?114)/20

Then, simplify the fraction

x=(8±?114)/10

 

[flora33]

Thank you both! I really appreciate your input.

=)
Flora