Match the equation on the left to its equivalent on the right.

y = x^2 - 1x - 20
y = (x + 8) (x + 11)
y = x^2 - 6x +16
y = (x + 4)^2 - 5

A) y = x ^2 - 1x - 20
B) y = (x - 3)^2 + 7
C) y = (x + 4) (x - 5)
D) y = x^2 + 19x + 88

1 answer

Let's break down the given equations one by one and match them with their equivalents:

  1. Starting with y = x^2 - 1x - 20 (A): To factor this, we find two numbers that multiply to -20 and add to -1:

    • These numbers are -5 and 4, so we can factor it as y = (x - 5)(x + 4), matching with C) y = (x + 4)(x - 5).
  2. Next, y = (x + 8)(x + 11) (B): We can expand this:

    • y = x^2 + 11x + 8x + 88 = y = x^2 + 19x + 88, matching with D) y = x^2 + 19x + 88.
  3. Now checking y = x^2 - 6x + 16 (C): We can complete the square or check for factors:

    • Completing the square: y = (x - 3)^2 + 7. This matches with B) y = (x - 3)^2 + 7.
  4. Finally, y = (x + 4)^2 - 5 (D):

    • Expanding this: y = (x^2 + 8x + 16 - 5) = x^2 + 8x + 11, but there are no further equivalents listed.

So here are the matches:

  • A) y = x^2 - 1x - 20 → C) y = (x + 4)(x - 5)
  • B) y = (x - 3)^2 + 7 → C) y = x^2 - 6x + 16
  • C) y = (x + 4)(x - 5) → A) y = x^2 - 1x - 20
  • D) y = x^2 + 19x + 88 → B) y = (x + 8)(x + 11)

Final matches:

  1. A ↔ C
  2. B ↔ C
  3. C ↔ A
  4. D ↔ B