Thread: Cubic Equation

Solve the cubic equation . Hence solve the equation

I have already solved the cubic equation however the 2nd part makes no sense to me.

Answers to cubic equation is

MY GUESS is that the solution to solving part 2 is changing the y in 8y+12 to (y+1) so as to substitute y+1 = x

Originally Posted by Punch

Solve the cubic equation . Hence solve the equation

I have already solved the cubic equation however the 2nd part makes no sense to me.

Answers to cubic equation is

MY GUESS is that the solution to solving part 2 is changing the y in 8y+12 to (y+1) so as to substitute y+1 = x

....

Then y + 1 = x ....

sorry but how did you get the y+1 for the 8 and an extra 8 popping out?

can you show me a more detailed working as i am not very expert in maths

Originally Posted by Punch

sorry but how did you get the y+1 for the 8 and an extra 8 popping out?

can you show me a more detailed working as i am not very expert in maths

You're expected to know that 8(y + 1) = 8y + 8 and therefore 8y = 8(y + 1) - 8.

And it should be clear why I wrote 8y as 8(y + 1) - 8.

By the way, I see from the time stamps that you spent exactly 2 minutes thinking about my reply (even less if the time taken to type your reply is taken into account). You're expected to put in much more effort than 2 minutes when trying to understand the help you get given.

Originally Posted by mr fantastic

By the way, I see from the time stamps that you spent exactly 2 minutes thinking about my reply (even less if the time taken to type your reply is taken into account). You're expected to put in much more effort than 2 minutes when trying to understand the help you get given.