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 + 8x + 11
B) y = (x - 3)^2 + 7
C) y = (x + 4) (x - 5)
D) y = x^2 + 19x + 88

1 answer

To match the equations on the left with their equivalent forms on the right, we first need to check the provided equations and factor or expand them as necessary.

  1. y = x^2 - 1x - 20

    • This equation can be factored. We need two numbers that multiply to -20 and add to -1. Those numbers are 4 and -5.
    • So, \(y = (x - 5)(x + 4)\).
    • Matches with C) y = (x + 4) (x - 5).
  2. y = (x + 8)(x + 11)

    • We can expand this:
    • \(y = x^2 + 11x + 8x + 88 = x^2 + 19x + 88\).
    • Matches with D) y = x^2 + 19x + 88.
  3. y = x^2 - 6x + 16

    • We can complete the square or analyze the quadratic.
    • Rewrite: \(y = (x - 3)^2 + 7\).
    • This is because \((x - 3)^2\) expands to \(x^2 - 6x + 9\), and adding 7 gives the correct number.
    • Matches with B) y = (x - 3)^2 + 7.
  4. y = (x + 4)^2 - 5

    • Rewrite by expanding:
    • \(y = (x^2 + 8x + 16 - 5) = x^2 + 8x + 11\).
    • Matches with A) y = x^2 + 8x + 11.

So, the final match is:

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