Question

CALCULE A EQUAÇÕES PELA FORMULA BASKARA

x²-15x+36=0
x²+4x-45=0
2x²-50=30
7x²+21x=0

Answer 1

a)x² - 15 x + 36 = 0
Δ = b² - 4.a.c
Δ = (-15)² - 4 . 1 . 36
Δ = 225   - 144
Δ = 81 ⇒√81 = 9
x = - b + ou - 9/2.1
x´= -(-15) + 9/2
x´= +15 +9 /2
x´= 24/2 ⇒ 12
x´´ = 15 - 9 / 2
x´´ = 6/2 ⇒3
s = {2, 3 }
b)x² + 4 x - 45 = 0
Δ = b² - 4 .a.c
Δ = 4² - 4 . 1 . -45
Δ = 16 + 180
Δ = 196 ⇒ √ 196 = 14
x = - b + ou - 14/2.1
x´= -4 + 14/2
x´= 10/2 ⇒ 5
x´´ = -4 - 14/2
x´´ = -18/2 ⇒-9
S = {5 ; -9 }
c)2 x² - 50 = 30
2 x² -50 -30 = 0
2 x² - 80 = 0
x² = 80/2
x² = 40
x = √ 40
x´= + 2√10
x´´ = - 2 √ 10
S = {+ 2√10 ; - 2 √10)
d)7 x² + 21  x = 0
7 x(x + 3 ) = 0
7 x = 0
x = 0/7
x = 0
x + 3 = 0
x = - 3
S ={0 ; -3 }