How would you do 7x squared + 27xy + 18y squared? I'm so used to the format of x squared + x + ___(insert number here)

Anima
Feb 3, 2015

#1**+5 **

I expect you want me to factorize it?

$$\\7x^2+ 27xy + 18y^2\\$$

This is a tough one.

We want to find 2 numbers that mult to 7*18 and add to 27

prime factors of 7*18 are 7*3*3*2 I notice straight off that 21+6=27

so the numbers are 21 and 6

change 27xy into 21xy+6xy

$$\\7x^2+ 27xy + 18y^2\\

=7x^2+ 21xy +6xy+ 18y^2\\

=7x(x+3y)+6y(x+3y)\\

=(7x+6y)(x+3y)$$

Do you understand Anima ?

Melody
Feb 3, 2015

#1**+5 **

Best Answer

I expect you want me to factorize it?

$$\\7x^2+ 27xy + 18y^2\\$$

This is a tough one.

We want to find 2 numbers that mult to 7*18 and add to 27

prime factors of 7*18 are 7*3*3*2 I notice straight off that 21+6=27

so the numbers are 21 and 6

change 27xy into 21xy+6xy

$$\\7x^2+ 27xy + 18y^2\\

=7x^2+ 21xy +6xy+ 18y^2\\

=7x(x+3y)+6y(x+3y)\\

=(7x+6y)(x+3y)$$

Do you understand Anima ?

Melody
Feb 3, 2015