You are Here: Home >< A-levels

# Hence solve the equation - OCR Maths

Announcements Posted on
Would YOU be put off a uni with a high crime rate? First 50 to have their say get a £5 Amazon voucher! 27-10-2016
1. Solve the equation y²-7y+12=0

Hence solve the equation x4-7x²+12=0

I understand how to factorise the first part but how do i use that to help with the second equation.
2. so the first part factorised is (y-3)(y-4)
the second equation is pretty much the same it just has different powers of x
so you take the first answer switch the y's for x's and make it x squared because x^2 times x^2 is x^4
3. The second equation has just used the substitution of y = x^2, so in your answer to part a), do the same and replace y with x^2 and solve this.
4. Thank you but why do you use x^2?
5. (Original post by pbms0101)
Thank you but why do you use x^2?
Well, what happens when you put y = x^2 into the new equation you have been asked to solve?

Also, if you quote someone like I have done so now, they will know you have responded
6. (Original post by pbms0101)
Thank you but why do you use x^2?
You have

We can make it look like a quadratic by saying:

Now let and you get

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: September 24, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### University open days

Is it worth going? Find out here

Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets