Question

Me ajudem! -X*+13X-42=0
Obs: * = Ao quadrado

Answer 1

-x² + 13x - 42 = 0

a = -1; b = 13; c = -42

x = [- b ± √(b² - 4ac)] / 2a
x = [- 13 ± √(13² - 4 · [-1] · [-42])] / 2 · (-1)
x = [- 13 ± √(169 - 168)] / -2
x = [- 13 ± √1] / -2
x = [- 13 ± 1] / -2
x' = [- 13 + 1] / -2 = -12 / -2 = 6
x'' = [- 13 - 1] / = -14 / -2 = 7

Espero ter ajudado. Valeu!

Answer 2

-x²+13x-42=0
A=-1, B=13, C=-42

Δ = b²-4.a.c
Δ=13²-4.(-1).(-42)=
Δ=169-168= 1

x= -b±√Δ
x=-13±√1/2(-1)= -13±1/-2

x'=-13+1/-2= -12/-2= 6

x"=-13-1/-2= -14/-2= 7

S:{6;7}