4x2 +9y2 = 72 x - y2 = -1
Select all of the following that are solutions to the system shown.
Solve?

Step-by-step explanation:

x - y² = -1     ⇒   - y² = - x - 1    ⇒    y² = x + 1   {x≥-1}

4x² + 9y² = 72

4x² + 9(x + 1)² = 72

4x² + 9(x² + 2x + 1) = 72

4x² + 9x² + 18x + 9 - 72 = 0

13x² + 18x - 63 = 0     ⇒   a = 13,  b = 18,  c = -63

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europa2433

step-by-step explanation: