10(3x−2)^2−60=0 Solve for x using the quadratic equations.
The answer I got was 2/3(+or-)(sqrt6)/3. Was told that the answer was wrong.
My steps were adding 60, 10(3x-2)^2=60, then divide by 10, (3x-2)^2=6, then sqrt both sides, 3x-2=sqrt6, then add 2 and divide by 3.
Pope
Favorite Answer
Your answer is correct. Could it be that the issue is with tour presentation? With so many people engaged in online learning, they need to learn to communicate their work and their answers through a keyboard.
I see that you wrote this: "3x-2=sqrt6"
That is only half right. Somewhere in there "sqrt6" was changed to "(+or-)(sqrt6)". That is correct, but if you pulled that off with no explanation, that is not so good.
Your running commentary is not very clear. We have mathematical notation for good reason. Let the calculations speak for themselves.
10(3x - 2)² - 60 = 0
10(3x - 2)² = 60
(3x - 2)² = 6
3x - 2 = ±√(6)
3x = 2 ± √(6)
x = 2/3 ± √(6)/3
Oh, and about that "using the quadratic equations" part of the instructions, that makes little sense. You were given nothing but a quadratic equation, so there is no way to reach an answer, right or wrong, without using the quadratic equation.
?
Your answer is correct but that is not what they wanted you to do. They asked you to use the quadratic equation. You did not do that. You solved it algebraically.
To use the quadratic formula, expand the expression and write
in the form ax² + bx + c = 0.
Now apply the quadratic eqs.
You should get the same answer you found.