Question

11. What values of a, b, and c make this equation true?

Answer 1

9514 1404 393

Answer:

  A,  a = 4, b = -3, c = 3

Step-by-step explanation:

Expanding the left side gives ...

  2x^2 -x -10 +ax^2 +bx +c

  = (2 +a)x^2 +(b -1)x +(c -10)

Equating coefficients with terms on the right side gives ...

  x^2: (2 +a) = 6   ⇒   a = 4 . . . . . . eliminates choice C

  x: (b -1) = -4   ⇒   b = -3 . . . . . . . . eliminates choices B, D

  constant: c -10 = -7   ⇒   c = 3 . . . confirms choice A