SAT Math hard problem on the test Quadratic Equation

#math #sat

0:00 - Complete the square
1:30 - Solve for K
2:09 - Solve for X

This is a harder question on the sat that covers systems of quadratic equations. You will need to know how to complete the square. If you need help with that, there are videos below.

Completing the square when a = 1

Completing the square a is not 1

[bobbyv]

You can do substitution and eliminate k
(Rearrange the 2nd equation to get k=2x-12)
then you are left with a quadratic:
(x-2)(x-10)

X=2, 10.

[harshprajapati]

I'm not even from USA but I like you solving these questions as they are from my syllabus