Question

PLEASE HELP

19- 4x + x² can be written in the form
(x + a)² + b, where a and b are numbers.
Work out the values of a and b.

Answer 1

Answer: (x-2)^2+15

Explanation:

Given x^2-4x+19

=here b=-4 and c=19

B=b/2=-4/2=-2

C=c-B^2=19-(-2)^2=19-4-15

so

(x-B)^2+C

(x-2)^2+15

Answer 2

Explanation:

so, let's do the multiplications and squaring. and then compare the result with the target.

(x + a)² + b = x² + 2ax + a² + b

and the original expression is

x² - 4x + 19

x² = x² done

2ax = -4x

2a = -4

a = -2

a² + b = 19

(-2)² + b = 19

4 + b = 19

b = 15

so, the result is

(x - 2)² + 15