$x+2y+z=5$
$2x+y+\alpha z=5$
$8x+4y+\beta z=18$
has no solution. Then $\frac{\beta}{\alpha}$ is equal to :
We are given a system of linear equations:
This system is stated to have no solution. We need to determine the value of the ratio $\frac{\beta}{\alpha}$.
Represent the system using an augmented matrix and apply row operations to simplify it.
The initial augmented matrix is:
| 1 | 2 | 1 | | | 5 |
| 2 | 1 | $\alpha$ | | | 5 |
| 8 | 4 | $\beta$ | | | 18 |
Perform row operations $R_2 \rightarrow R_2 - 2R_1$ and $R_3 \rightarrow R_3 - 8R_1$:
| 1 | 2 | 1 | | | 5 |
| 0 | -3 | $\alpha - 2$ | | | -5 |
| 0 | -12 | $\beta - 8$ | | | -22 |
Perform row operation $R_3 \rightarrow R_3 - 4R_2$:
| 1 | 2 | 1 | | | 5 |
| 0 | -3 | $\alpha - 2$ | | | -5 |
| 0 | 0 | $\beta - 4\alpha$ | | | -2 |
For a system of linear equations represented by an augmented matrix to have no solution, the row-reduced form must contain a row equivalent to $[0 \ 0 \ \dots \ 0 \ | \ k]$, where $k \neq 0$.
Looking at the last row of our reduced matrix, it corresponds to the equation:
$(\beta - 4\alpha)z = -2$
This equation yields no solution if the coefficient of $z$ is zero and the constant term is non-zero.
From the condition $\beta - 4\alpha = 0$, we can write:
$\beta = 4\alpha$
To find the ratio $\frac{\beta}{\alpha}$, we divide both sides by $\alpha$. This is permissible because the options provided are finite numbers, implying $\alpha \neq 0$.
$\frac{\beta}{\alpha} = \frac{4\alpha}{\alpha}$
$\implies \frac{\beta}{\alpha} = 4$
The value of the ratio $\frac{\beta}{\alpha}$ is 4.
Let f and g be functions satisfying $f(x+y) = f(x)f(y), f(1) = 7$ and $g(x+y) = g(xy), g(1) = 1$, for all $x, y \in \mathbb{N}$. If $\sum_{x=1}^{n} \left(\frac{f(x)}{g(x)}\right) = 19607$, then n is equal to :
Let S be the set of the first 11 natural numbers. Then the number of elements in $A = \{B \subseteq S : n(B) \geq 2$ and the product of all elements of B is even is ________.