Case 4: Two Solutions


Line: y = -2x + 11
Parabola: y = 2x2 - 8x + 11



Graphical Solution:


There are two solutions.
(0, 11) is in both tables, so it is one solution.
The other point (3, 5) is in the parabola table, and a quick check shows that it's in the line's table.
Solutions (0, 11) and (3, 5)


Algebraic Solution:

y = -2x + 11
y = 2x2 - 8x + 11

Use Comparison:
2x2 - 8x + 11 = -2x + 11
2x2 - 6x = 0
Solve by factoring
2x(x - 3) = 0
x = 0  or  x = 3

Substitute each in y = -2x + 11:
x = 0:  y = -2(0) + 11 = 11  Solution (0, 11)
x = 3:  y = -2(3) + 11 = 5  Solution (3, 5)


Intro | No Solution | One Solution (V) | One Solution (T) | Two Solutions



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