Respuesta:
2x - 0.5x = 30
x = 20
Explicación paso a paso:
Llamemos "x" a la incógnita, el número desconocido.
Cuando nos referimos al doble de un número, es lo mismo que 2x.
Cuando nos referimos a la mitad de un número, es lo mismo que 0.5 x.
Consideremos que al doble de un número (2x) se le resta su mitad 0.5x) y se obtiene 30. La ecuación resultante es:
2x - 0.5x = 30
1.5x = 30
x = 30/1.5 = 20
Answer:
Step-by-step explanation:
If the smallest number is 'x', then the other number = x +1
x*(x+1)= 420
Use distributive property
x*x + x*1 = 420
x² + x - 420 =0 ------> this is the required quadratic equation.
Here you have to find which each variable is, for this you start of picking one equation,
x + 2y + 6z = 4
-3x + 2y - 2 = -4
4x + 2z = 16
depending the equation you pick you multiply that by a certain number that will give you the opposite of one of the other equations,
-1(x + 2y + 6z = 4)
= -x -2y - 6z = -4
With this you add or subtract it with the equation that has the same number or variable, or both,
In this case it will be the equation,
-3x + 2y + 6z = 4
You can use this one or the third equation since both have a positive 2y which will cancel with -2y from the new equation,
-x - 2y - 6z = -4
-3x + 2y -z = -4
= -4x -7z = -8
Now you since you just eliminated the variable (y) you now have 2 variables, and the last equation has only 2 variables, meaning now you find the answer to those to equations,
-4x -7z = -8
4x + 2z = 16
= -5z = 8
Now leave the variable by itself,
z = 8/5
Now you found the variable (z), with this just substitute on one of the equations we used to find (z) so you can find (x), after that substitute those answered to on of the original equations so you can find (y)
There are 64 people in the room.
Since the ratio for women increases 1 when 8 women enter the room, for every time there is 1 in the ratio there are 8 people. That means that originally you have to do 3x8 and 4x8. You get 24 and 32 which equals 56. Then when 8 more women enter the room, you get 64.
We see from the attached, that kite area = product of the diagonals / 2
The diagonals could be 12 by 8 or
6 by 16 or
3 by 32, etc
It cannot be narrowed down any further.
