Question

como resolver este sistema de acuaciones lineales -8x-10y=-7 y -50x-75y=-42

Answer 1

pero sale x = -35.28

               y = 30.1538461538

Answer 2

RTA

Rta:

X = 21/20

Y = -7/50

Ecuacion 1:

-8X - 10Y = -7

Ecuacion 2:

-50X - 75Y = -42

Reescrbiendo:

8X + 10Y = 7 (1)

50X + 75Y = 42 (2)

En (1):

8X + 10Y = 7

8X = 7 - 10Y

X = (7 - 10Y)/8

Ahora reemplazo este valor de X en 2:

50[(7 - 10Y)/8] + 75Y = 42

25[(7 - 10Y)/4] + 75Y = 42

(175 - 250Y)/4 + 75Y = 42

(175 - 250Y)/4 + 300Y/4 = 42

(175 - 250Y + 300Y)/4 = 42

175 + 50Y = (42)(4)

175 + 50Y = 168

50Y = 168 - 175

50Y = -7

Y = -7/50

Ahora reemplazando el valor de Y = -7/50

X = (7 - 10Y)/8

X = [(7 - 10(-7/50))]/8

X = [(7 + 7/5)]/8

X = [(35/5 + 7/5)]/8

X = [(42/5)]/8

X = (42)/[(5)(8)]

X = (42)/(40)

X = 21/20

Rta:

X = 21/20

Y = -7/50