Question

resolver ? x²+x-30=0

Answer 1

a=1
b= 1
c=-30 ∆= b² - 4. ac
∆ = 1 - 4 . 1 . -30
∆= 1 + 120
∆= 121

x= -b +- √∆ ÷ 2a
x = -1 +- √121 ÷ 2. 1
x = -1 +- 11 ÷ 2

x'= -1 + 11 ÷ 2
x'= 10 ÷ 2
x'= 5

x''= -1 - 11 ÷ 2
x''= -12 ÷ 2
x''= -6

S= {5; -6}