Question

Factorise the following quadratic:
e² - 17e + 70

Answer 1

Explanation:

I think you're supposed to use the quadratic formula Samanth

Know it?

-b ±
`\sqrt{b^(2)-4ac }` / (2a)

so for starters, let me mention, that if 4ac happens to be greater than
`b^(2)` contrary to what all math teacher say, about not being able to taking the square of a negative number, you can, but you just end up with a complex number in the form of A + Bi , where 'i' represents
`√(-1)` anyway,

for the given equation

A = 1

B = -17

C = 70

{ -(-17) ±
`\sqrt{(-17)^(2)-4*1*70 }` } / (2*1)

{ 17 ±
`√(289-280)` } / 2

wow, now i'm glad I mentioned about the 4ac being greater :P

it was close, huh

{ 17 ±
`√(9)` } / 2

{ 17 ± 3 } /2

let's take each case now, the plus and then the minus

{ 17+3 } /2

20 /2

10

now the minus

{17 - 3 } / 2

14 /2

7

now that i've done all that work, I think we could have just done this by inspection :P

(e-7)(e-10)

anyway, hope that helps, ask if you have any questions :)