I'm assuming Petra is only removing blue marbles, and she is keeping the 2 red marbles the whole time.
If so, then she starts with 49 blue marbles and ends up with 49-x blue marbles after removing x blue marbles. Overall she starts with 49+2 = 51 marbles total and ends up with 51-x marbles total after taking away x blue marbles.
(49-x)/(51-x) represents the proportion of blue marbles after we take those blue ones away. We want the proportion to be 0.90
(49-x)/(51-x) = 0.90
49-x = 0.90(51-x)
49-x = 0.90(51)+0.90(-x)
49-x = 45.9-0.90x
-x+0.90x = 45.9-49
-0.10x = -3.1
x = -3.1/(-0.10)
x = 31
<h3>Petra must remove 31 blue marbles so that 90% of the marbles are blue.</h3><h3>Answer: (E) 31</h3>
Answer:
1-
2X + 3Y = 330
2-
X + Y + Z = 3890
3-
1/3X + 2/3X = X
4-
X + Y = 27
Step-by-step explanation:
Para plantear ecuaciones para las siguientes situaciones se deben realizar los siguientes razonamientos lógicos:
1- Juan compró 2 panchos y 3 hamburguesas y le cobraron $330.
Panchos = X
Hamburguesas = Y
2X + 3Y = 330
2- Realizo un pago de la factura de luz, agua y cable en total me cobran $3890.
Luz = X
Agua = Y
Cable = Z
X + Y + Z = 3890
3- Un padre reparte un dinero X que recibió entre su esposa y su hijo, a su esposa le da el doble que al hijo.
Esposa = 2/3X
Hijo = 1/3X
1/3X + 2/3X = X
4- En el salón de clase hay 27 alumnos entre mujeres y varones.
Mujeres = X
Varones = Y
X + Y = 27
The answer is -2
Hope this helps!
A. -2/3 because you would go down two and then to the right three. <em>I hope that helps.</em>
X * Y * 9 = 432
Divide 9 from both sides
X * Y = 48
That gives you a variety of answers
1 * 48
2 * 24
4 * 12
6 * 8