Question

resolva as equaçoes

a) x²-6x+9=4

b) x²-14x+49=0

c) x²+8x+16=0

d) x²+8x+16=1

e) x²-8x+16=1

f) x²-8x+16=4

g) x²+10x+25=0

h) x²-10x+25=9

i) 4x²-12x+9=0


j) 9x+6x+1=0

Answer 1

a) x2 - 6x + 9 = 4

x2 - 6x + 9 - 4 = 0

x2 - 6x + 5 = 0

a = 1  b  =  - 6  c = 5

delta = b2 - 4 . a. c

delta = ( - 6 )2 - 4 . 1 . 5

delta = 36 - 20

delta = 16

x =  - b + - raiz quadrada de delta sobre 2 .a

x = - ( - 6 ) + - raiz quadrada de 16 sobre 2 .1

x = 6 + - 4 / 2

x ' = 6 - 4 /2

x' = 2 / 2

x' = 1             x" = 6 + 4 /2

                     x" = 10 / 2            x" = 5                   S = { 1 ,5 }