On the third line you have the +25 and -25
they got rid of the -25
To do this they removed it from the bracket to the outside of the function
But since it was in the bracket you cannot forget to multiply by the 3 that was on the outside
This made the -25 a -75....and when you add the -75 and 41 you get -34
We did this qs in class so we change the equation into the vertex form
Here is the solution.
Y=3x^2+30x+41
y=3(x^2+10x)+41
Y=(x^2+10x+25-25)+41
Y=3(x+5)^2-34
I understand everything expected I don't know how we get -34, can you explain please?
1 answer
1 answer