Question

resolva as equações ײ-10×+21=0

Answer 1

∆= b²-4ac
∆= -10²-4.1.21
∆=100-84
∆= 16

x=-b+/-√∆/2a
x=10+/-4/2.1
x'= 10+4/2
x'= 7
x"=10-4/2
x"= 3

Espero ter ajudado :)