Question

(x-5) (x-2)=30
es para un examen​

Answer 1

Respuesta:

(x-5)(x-2) = 30

(x)²+(-5-2)x+((-5)(-2)) = 30

x²+(-7)x+(-(-10)) = 30

x²-7x+10 = 30

x²-7x+10-30 = 30-30

x²-7x+(-20) = 0

x²-7x-20 = 0

x²-7x-20+20 = 0+20

x²-7x = 20

x²-7x+(-7/2)² = 20+(-7/2)²

x²-7x+(49/4) = 20+(49/4) ; 20 = 80/4

(x-7/2)² = 80/4+49/4

(x-7/2)² = 129/4

√(x-7/2)² = √(129/4)

√(x-7/2)² = √(129)/√(4)

√(x-7/2)² = √(129)/2

x-7/2 = +-√(129)/2

x-7/2+7/2 = 7/2+-√(129)/2

x = 7/2+-√(129)/2

x1 = (7-√(129))/2

x1 = -2,179 ( Aproximadamente )

x2 = (7+√(129))/2

x2 = 9,179 ( Aproximadamente )

Explicación paso a paso: