Looking for answers? Westonci.ca is your go-to Q&A platform, offering quick, trustworthy responses from a community of experts. Connect with a community of experts ready to help you find accurate solutions to your questions quickly and efficiently. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

If [tex]\( (1, 2) \)[/tex] is a solution of the system of equations
[tex]\[
\begin{cases}
(k+1)x + 2y = 7 \\
x - 4y = -7
\end{cases}
\][/tex]
then the value of [tex]\( k \)[/tex] is:

A) [tex]\( k = 0 \)[/tex]
B) [tex]\( k = 1 \)[/tex]
C) [tex]\( k = 2 \)[/tex]
D) [tex]\( k = 3 \)[/tex]


Sagot :

To determine the correct value of [tex]\( k \)[/tex], we need to solve the system of equations given by:

[tex]\[ \begin{cases} (k+1)x + 2y = 7 \\ x - 4y = -7 \end{cases} \][/tex]

We are given that [tex]\( x = 2 \)[/tex] and [tex]\( y = 1 \)[/tex].

First, let's substitute these values into the second equation to confirm the values of [tex]\( x \)[/tex] and [tex]\( y \)[/tex]:

[tex]\[ x - 4y = -7 \][/tex]
Substitute [tex]\( x = 2 \)[/tex] and [tex]\( y = 1 \)[/tex]:

[tex]\[ 2 - 4(1) = -7 \][/tex]
[tex]\[ 2 - 4 = -2 \neq -7 \][/tex]

There seems to be an inconsistency here considering the standard approach. However, let's proceed with the first equation to find the value of [tex]\( k \)[/tex] given the equations match the constants provided.

Substitute [tex]\( x = 2 \)[/tex] and [tex]\( y = 1 \)[/tex] into the first equation:
[tex]\[ (k+1)x + 2y = 7 \][/tex]

Substitute [tex]\( x = 2 \)[/tex] and [tex]\( y = 1 \)[/tex]:
[tex]\[ (k+1)(2) + 2(1) = 7 \][/tex]
Simplify:
[tex]\[ 2(k+1) + 2 = 7 \][/tex]
[tex]\[ 2k + 2 + 2 = 7 \][/tex]
[tex]\[ 2k + 4 = 7 \][/tex]
Subtract 4 from both sides:
[tex]\[ 2k = 3 \][/tex]
Divide by 2:
[tex]\[ k = \frac{3}{2} \][/tex]

Thus, there is no integer value of [tex]\( k \)[/tex] from the given options ([tex]\( k = 0 \)[/tex], [tex]\( k = 1 \)[/tex], [tex]\( k = 2 \)[/tex], [tex]\( k = 3 \)[/tex]) that satisfies these equations with [tex]\( x = 2 \)[/tex] and [tex]\( y = 1 \)[/tex]. Hence, the correct option for [tex]\( k \)[/tex] does not exist within the provided choices.

But since we are to choose from the given options, we conclude that:

None of the given values of [tex]\( k \)[/tex] satisfy the equations with [tex]\( x = 2 \)[/tex] and [tex]\( y = 1 \)[/tex].

Thus the correct answer is:
```
[]
```