Question

Determine o valor de p
2x+px+16=0,x=2

Answer 1

2. (2+p+2+16) =0
propriedade distributiva, famoso chuveirinho

4+2p+4+32=0
2p= -32-4-4
2p= -40
p= -40/2
p= -20

Answer 2

2x² + px + 16 = 0
x = 2
2(2)² + p/2 + 16 = 0
2(4 ) + p/2 + 16 = 0
8 + p/2 + 16 = 0
24 + p/2 = 0
p/2 = - 24/1
p = -24 * 2
p = - 48 ****

b
x² + 7x + ( p + 1 ) = 0
x =  - 3
( -3)² + 7 ( -3) + ( p + 1 ) = 0
9 - 21 + ( p + 1) = 0
-12 + ( p + 1 ) = 0
p - 11 = 0
p = 11 *****

c
5x² - ( 6 - p ).x - 25 = 0
x = -5
5x² - 6x + px - 25 = 0
5(-5)² - 6 ( -5) + p( -5) - 25 = 0
5 * 25 + 30 - 5p - 25 = 0
125 + 30 - 5p - 25 = 0
130 - 5p = 0
-5p = - 130
5p = 130
p = 130/5 = 26 ****

d
3x² - 9x + ( p/2) = 0
x = 1
3 (1)²  - 9 ( 1 ) + p/2 = 0
3 - 9 + p/2  = 0
-6 + p/2 = 0
p/2 = 6/1
p = 2 * 6
p = 12 ****