Update Quadratic Equations.md

Grade 10/Math/MPM2DZ/Math Oral Presentation Questions/Quadratic Equations.md

@@ -179,8 +179,6 @@ When $`h = 0`$, the ball hits ground, so:
 
 $`-3.2t^2 + 12.8 + 1 = 0`$
 
-$`t = \dfrac{-12.8 \pm \sqrt{12.8^2 - 4(3.2)}}{-6.4}`$
-
 $`t = \dfrac{12.8 \pm \sqrt{151.04}}{6.4}`$
 
 $`\because t \ge 0`$
@@ -199,7 +197,6 @@ $`16t^2 - 96t + 128 = 0`$
 
 $`t^2 - 6t + 8 = 0`$
 
-
 $`(t-2)(t-4)`$, at seconds $`2`$ and $`4`$, the rocket reaches $`128m`$.
 
 ### Question 5 b)
@@ -212,8 +209,6 @@ $`-40d^2 + 200d = 300 - 40d`$
 
 $`40d^2 - 240d + 300 = 0`$
 
-$`4d^2 - 24d + 30 = 0`$
-
 $`2d^2 - 12d + 15 = 0`$
 
 $`d = \dfrac{12 \pm \sqrt{24}}{4}`$