Algebra Know-It-ALL

(Marvins-Underground-K-12) #1
Next, let’s check (0,1) in the original two-variable quadratic equation:

2 x^2 −y+ 1 = 0
2 × 02 − 1 + 1 = 0
2 × 0 − 1 + 1 = 0
0 − 1 + 1 = 0
− 1 + 1 = 0
0 = 0

Finally, let’s check (−3/2,11/2) in that same equation:

2 x^2 −y+ 1 = 0
2 × (−3/2)^2 − 11/2 + 1 = 0
2 × 9/4 − 11/2 + 1 = 0
9/2− 11/2 + 1 = 0
−2/2+ 1 = 0
− 1 + 1 = 0
0 = 0


  1. Here are the two equations in their original forms:


3 x+y− 1 = 0

and

2 x^2 − 3 x−y+ 3 = 0

We can manipulate these to obtain the following functions of x:

y=− 3 x+ 1

and

y= 2 x^2 − 3 x+ 3

When we mix the right sides of these equations, we obtain

− 3 x+ 1 = 2 x^2 − 3 x+ 3

which can be rewritten in standard form as the quadratic equation

2 x^2 + 2 = 0

Chapter 27 701
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