Question

URGENTEEEEEEEE!!

Resolva as seguintes equações admitindo o U =R

a) X² - 49 = 0
b) X² - 5 = 0
c) 3y² - 75 = 0
d) 4t² - 9 = 0
e) W² - 5 w = 0
f) - 2x² + 6x = 0
g) (3x + 4) (2x - 1) = - 4
h) 2x² + 4x = 0
i) (y + 5) (y + 3) = 15
j) - 5b² + 75 = 0​

Answer 1

Resposta:

a) X² - 49 = 0  ==>x=±√49  ==>x=±7

b) X² - 5 = 0 ==>x=±√5

c) 3y² - 75 = 0 ==> y²=75/3  ==>x²=25  ==>x=±√25=±5

d) 4t² - 9 = 0 ==>x²=9/4 ==>x=±√(9/4) =±3/2

e) W² - 5 w = 0 ==>w*(w-5)=0

w=0

w-5=0  ==>w=5

f) - 2x² + 6x = 0

-2x*(x+3)=0

-2x=0  ==>x=0

x+3=0 ==>x=-3

g) (3x + 4) (2x - 1) = - 4

6x²-3x+8x-4=-4

6x²+5x=0

x*(6x+5)=0

x=0

6x+5=0  ==>x=-5/6

h) 2x² + 4x = 0

2x*(x+2)=0

2x=0  ==>x=0

x+2=0 ==>x=-2

i) (y + 5) (y + 3) = 15

y²+3y+5y+15=15

y²+8y=0

y*(y+8)=0

y=0

y+8=0 ==>y=-8

j) - 5b² + 75 = 0​

-5b²=-75

b²=15  ==>b=±√15