Question

a) x² + 25 = 0
b) 11x? – x = 0
49x? = 36
d) 3x² – 27x = 0
e) xʻ– 14 = 0
f) –25x?- 15x = 0​

Answer 1

Resposta

A) x²-15x=0

x (x - 15) = 0

x= 0

x - 15 = 0

x = 15

S = {0 , 15}

B)x²-81=0

x² = 81

x = √81

x = 9

S = {9}

C)X²-121=0

x² = 121

x = √121

x = 11

S = {11}

D)3X²-5X=0

x (3x - 5) = 0

x = 0

3x - 5 = 0

3x = 5

x = 5 / 3

S= {0 , 5/3}

E)x²-x=0

x(x - 1) = 0

x = 0

x - 1 = 0

x = 1

S = {0 , 1}

F)9x²-16=0

9x² = 16

x² = 16 / 9

x = √16 / √9

x = 4 / 3

S= { 4/3 }

G)x²+25=0

x² = -25

x = √-25

x = √-1 . 5²

x = 5√-1

S = {5√-1}

H)11x²-x=0

x (11x - 1) = 0

x = 0

11x - 1 = 0

11x = 1

x = 1 / 11

S = {0 , 1/11}

I)49x²=36

x² = 36 / 49

x = √36 / √49

x = 6/7

S = { 6/7 }

J)3x²-27x=0

x (3x - 27) = 0

x = 0

3x - 27 = 0

3x = 27

x = 27 / 3

x = 9

S= {0, 9}

K)x²-14=0

x² = 14

x = √14

S = { √14 }

L)-25x²-15x=0

5x (-5x - 3) = 0

5x = 0

x= 0

-5x - 3 = 0

-5x = 3 .(-1)

5x = -3

x = -3 / 5

S = {0, -3/5}