SOLUTION: Please help solve this equation y=3x^2-20x VERTEX?

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Question 1049421: Please help solve this equation y=3x^2-20x VERTEX?
Found 3 solutions by Alan3354, josmiceli, advanced_Learner:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Do you want to solve, as in find the zeroes?
Or find the vertex?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+y+=+3%2Ax%5E2+-+20x+
The formula for the x-value of the vertex is:
+x%5Bv%5D+=+-b%2F%282a%29+
when the form of the equation is:
+y+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+
So, in this case:
+a+=+3+
+b+=+-20+
----------------
+x%5Bv%5D+=+-%28+-20+%29+%2F+%282%2A3%29+
+x%5Bv%5D+=+10%2F3+
-------------------
Plug this back into the equation to get +y%5Bv%5D+
+y%5Bv%5D+=+3%2A%2810%2F3%29%5E2+-+20%2A%2810%2F3%29+
+y%5Bv%5D+=+100%2F3+-+200%2F3+
+y%5Bv%5D+=+-100%2F3+
The vertex is at:
( 10/3, -100/3 )
---------------------------------
check answer:
Here's the plot:
+graph%28+400%2C+400%2C+-10%2C+10%2C+-50%2C+50%2C+3x%5E2+-+20x+%29+

Answer by advanced_Learner(501) About Me  (Show Source):
You can put this solution on YOUR website!
y=3x%5E2-20x
vertex x part is -b%2F2a=--20%2F2%283%29=--20%2F6=20%2F6=10%2F3

Y part is
y=3x%5E2-20x at x=10%2F3
y=3%2A%2810%2F3%29%5E2-20%2A%2810%2F3%29 at x=10%2F3
y=3%28100%2F9%29-20%2810%2F3%29 at x=10%2F3
y=%28100%2F3%29-%28200%2F3%29 at x=10%2F3
y=-%28100%2F3%29 at x=10%2F3
Vertex is x=10%2F3 and y=-%28100%2F3%29
the Point (10/3,-100/3) is the vertex of the function
y=3x%5E2-20x

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