Question

Resolva as equações:
a)x²-14x+49
b)4x²-20x+25=0
c)4y²=4y-1
d)-²-6p=16p-25
e)x²-6x+9
f)x²+8x+16=0
g)4x²-12x+9=0

Answer 1

Olá Fabi

a) 

x² - 14x + 49 = 0

(x - 7)² = 0

x = 7

b)

4x² - 20x + 25 = 0

(2x - 5)² = 0

x = 5/2 

c)

4y² - 4y + 1 = 0

delta
d² = 16 - 16 = 0

y = 4/8 = 1/2 

d) 

-p² - 6p = 16p - 25

p² + 22p - 25 = 0

delta
d² = 22² + 4*25 = 584
d = 2√146 

p1 = (-22 + 2√146)/2 = -11 + √146
p2 = (-22 - 2√146)/2 = -11 - √146

e)

x² - 6x + 9 = 0

(x - 3)² = 0

x = 3

f)

x² + 8x + 16 = 0

(x + 4)² = 0

x = -4

g)

4x² - 12x + 9 = 0

delta
d² = 144 - 144 = 0
d = 0

x = 12/8 = 3/2

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