Question

resolva as questões, calculo e resposta.
${x}^{2} + 8x + 15 = 0$

$2 {x}^{2} - 7x + 6 = 0$

Answer 1

A) x² + 8x + 15 = 0

A= 1
B= 8
C= 15

∆= 8² - 4 • 1 • 15
∆= 64 - 60
∆= 4

x= - 8 ± √4 / 2 • 1
x = - 8 ± 2 / 2

x'= - 8 + 2 / 2 = - 6 / 2 = - 3
x''= - 8 - 2 / 2 = - 10 / 2 = - 5

S={( - 3 , -5)}

B) 2x² - 7x + 6 = 0

A= 2
B= - 7
C= 6


∆= (-7)² - 4 • 2 • 6
∆= 49 - 48
∆= 1


x= - (-7) ± √1 / 2 • 2
x= 7 ± 1 / 4

x' = 7 + 1 / 4 = 8 / 4 = 2
x''=7 - 1 / 4 = 6 / 4 (Simplifica por 2) = 3/2

S={( 2 , 3/2)}