How do you solve this simultaneous equation?

  • 0 votes

y= x^2 + 12
y= x + 14
??????????

Posted Thu 26th April, 2012 @ 17:59 by mightaswellbehezzyb

2 Answers

  • 2 votes

Since they are both equal to y, they must be equal to each other. Therefore:

x+14=x^2+12

Rearrange to:

x^2-x-2=0

Factorise (alternatively you can use the quadratic formula):

(x-2)(x+1)=0

Since anything times 0 is 0, then either x-2 or x-1 must be 0. Therefore x is:

x=2 or x=1

Answered Thu 26th April, 2012 @ 18:38 by Daniel
  • 2 votes

Daniel, you mean x = 2 or -1.

Answered Thu 26th April, 2012 @ 23:17 by Maleficent