Question

Can I get some help somebody? reward brainiest

Answer 1

Answer:

Step-by-step explanation:

1). x² - 8x

  To convert this expression into a perfect square trinomial,

  x² - 2(4x) + 4² = (x - 2)²

  Therefore , 4² = 16 should be added.

  Option (4) is the answer.

2). x² + 2x = 3

   x² + 2(1)(x) = 3

   x² + 2(1)(x) + 1 = 3 + 1 [By adding 1 on both the sides]

   (x + 1)² = 4

    x + 1 = ±2

    x = -3, -1

   Option (1) is the answer.

3). 3x²- 18x = 21

    x² - 6x = 7

    x² - 2(3x) = 7

    x² - 2(3x) + 3² = 7 + 3²

    (x - 3)² = 7 + 9

    (x - 3)² = 16

     x - 3 = ±4

     x = -1, 7