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lol4373
29.07.2021 •
Mathematics
Help mee pls plss fast
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Ответ:
Difference between a 1 inch button and ⅜ inch button
Ответ:
Respuesta: 12 estudiantes trajeron pilas
Solución:
Numero total de estudiantes: 30
Sea:
x: numero de estudiantes que trajeron pilas
y: numero de estudiantes que no trajeron pilas
x+y=30 (1)
La razón entre los estudiantes que trajeron pilas y los que no trajeron es como 2 es a 3:
Razón: r=x/y=2/3 (2)
Cuantos estudiantes trajeron pilas?
x=?
Tenemos un sistema de 2 ecuaciones con 2 incógnitas:
(1) x+y=30
(2) x/y=2/3
Vamos a resolver para x. Multiplicando en cruz en la segunda ecuación:
(2) 3x=2y
Depejando y: Dividiendo ambos lados de la ecuación entre 2:
3x/2=2y/2
3x/2=y
y=3x/2
Sustituyendo y por 3x/2 en la primera ecuación:
(1) x+y=30
x+3x/2=30
Sumando los términos en el lado izquierdo de la ecuación:
(2x+3x)/2=30
5x/2=30
Despejando x:
x=30*2/5
x=60/5
x=12