IDNLearn.com provides a user-friendly platform for finding and sharing accurate answers. Get the information you need from our community of experts who provide accurate and comprehensive answers to all your questions.

Which ordered pair [tex]\((p, r)\)[/tex] is the solution to the given system of linear equations?

[tex]\[
\begin{cases}
5p - 3r = 1 \\
8p + 6r = 4
\end{cases}
\][/tex]

A. [tex]\((-1, -2)\)[/tex]

B. [tex]\((-2, -1)\)[/tex]

C. [tex]\(\left(\frac{2}{9}, \frac{1}{3}\right)\)[/tex]

D. [tex]\(\left(\frac{1}{3}, \frac{2}{9}\right)\)[/tex]


Sagot :

To find the solution for the given system of linear equations:

[tex]\[ \begin{cases} 5p - 3r = 1 \\ 8p + 6r = 4 \end{cases} \][/tex]

we need to determine the values of [tex]\( p \)[/tex] and [tex]\( r \)[/tex] that satisfy both equations simultaneously.

### Step 1: Write down the equations
1. [tex]\( 5p - 3r = 1 \)[/tex]
2. [tex]\( 8p + 6r = 4 \)[/tex]

### Step 2: Normalize one of the equations, if possible
From the second equation, we can divide every term by 2 to simplify it:
[tex]\[ 4p + 3r = 2 \][/tex]

### Step 3: Rewrite the system
This changes our system to:
[tex]\[ \begin{cases} 5p - 3r = 1 \\ 4p + 3r = 2 \end{cases} \][/tex]

### Step 4: Add the equations
To eliminate [tex]\( r \)[/tex], add the two equations together:
[tex]\[ (5p - 3r) + (4p + 3r) = 1 + 2 \][/tex]

The [tex]\( -3r \)[/tex] and [tex]\( +3r \)[/tex] cancel each other out:
[tex]\[ 5p + 4p = 3 \][/tex]
[tex]\[ 9p = 3 \][/tex]

### Step 5: Solve for [tex]\( p \)[/tex]
Divide both sides of the equation by 9:
[tex]\[ p = \frac{3}{9} = \frac{1}{3} \][/tex]

### Step 6: Substitute [tex]\( p \)[/tex] back into one of the original equations
Use the first equation to solve for [tex]\( r \)[/tex]:
[tex]\[ 5p - 3r = 1 \][/tex]
Substitute [tex]\( p = \frac{1}{3} \)[/tex]:
[tex]\[ 5\left(\frac{1}{3}\right) - 3r = 1 \][/tex]
[tex]\[ \frac{5}{3} - 3r = 1 \][/tex]

### Step 7: Solve for [tex]\( r \)[/tex]
Isolate [tex]\( r \)[/tex] by moving the fraction to the other side:
[tex]\[ \frac{5}{3} - 1 = 3r \][/tex]
[tex]\[ \frac{5}{3} - \frac{3}{3} = 3r \][/tex]
[tex]\[ \frac{2}{3} = 3r \][/tex]
Divide both sides by 3:
[tex]\[ r = \frac{2}{3 \cdot 3} = \frac{2}{9} \][/tex]

### Step 8: Conclusion
The solution to the system of equations is:
[tex]\[ \left( p, r \right) = \left( \frac{1}{3}, \frac{2}{9} \right) \][/tex]

So, the correct ordered pair is [tex]\( \left( \frac{1}{3}, \frac{2}{9} \right) \)[/tex]. This matches the option: [tex]\( \left( \frac{1}{3}, \frac{2}{9} \right) \)[/tex].