Use a graphing tool to solve the system.

[tex]\[
\left\{\begin{array}{l}
4x - 15y = -43 \\
2x - 3y = -2
\end{array}\right.
\][/tex]

Which ordered pair is the best estimate for the solution to the system?

A. \((5.5, 4.3)\)
B. \((6.5, 5.2)\)
C. \((5.1, 4.8)\)
D. [tex]\((4.8, 5.2)\)[/tex]



Answer :

Let's solve this system of equations step-by-step to determine the best estimate for its solution.

We have the following system of linear equations:

[tex]\[ \left\{\begin{array}{l} 4 x - 15 y = -43 \\ 2 x - 3 y = -2 \end{array}\right. \][/tex]

To solve these equations, let's use the method of substitution or elimination. For simplicity, we'll use the elimination method to find the values of \( x \) and \( y \).

1. Step 1: Align the equations.
[tex]\[ 4 x - 15 y = -43 \quad \text{(Equation 1)} \][/tex]
[tex]\[ 2 x - 3 y = -2 \quad \text{(Equation 2)} \][/tex]

2. Step 2: Make the coefficients of \( x \) or \( y \) equal.
Multiply Equation 2 by 2 to make the coefficient of \( x \) equal to that in Equation 1:
[tex]\[ 2 (2 x - 3 y) = 2 (-2) \][/tex]
[tex]\[ 4 x - 6 y = -4 \quad \text{(Updated Equation 2)} \][/tex]

3. Step 3: Eliminate \( x \) by subtracting Equation 2 from Equation 1.
Subtract the updated Equation 2 from Equation 1:
[tex]\[ (4 x - 15 y) - (4 x - 6 y) = -43 - (-4) \][/tex]
[tex]\[ 4 x - 15 y - 4 x + 6 y = -43 + 4 \][/tex]
[tex]\[ -9 y = -39 \][/tex]
[tex]\[ y = \frac{-39}{-9} \][/tex]
[tex]\[ y = \frac{39}{9} \][/tex]
[tex]\[ y = 4.3333 \quad \text{(approximately)} \][/tex]

4. Step 4: Substitute \( y \) back into one of the original equations to solve for \( x \).
Using Equation 2:
[tex]\[ 2 x - 3(4.3333) = -2 \][/tex]
[tex]\[ 2 x - 13 = -2 \][/tex]
[tex]\[ 2 x = 11 \][/tex]
[tex]\[ x = \frac{11}{2} \][/tex]
[tex]\[ x = 5.5 \][/tex]

Thus, the solution to the system of equations is approximately \( (x, y) = (5.5, 4.3333) \).

Step 5: Compare the solution with the given choices.

The choices given are:
- \( (5.5, 4.3) \)
- \( (6.5, 5.2) \)
- \( (5.1, 4.8) \)
- \( (4.8, 5.2) \)

Step 6: Identify the closest match.

The closest option to \( (5.5, 4.3333) \) is:
- \( (5.5, 4.3) \)

Therefore, the best estimate for the solution to the system is:

Best Estimate:
[tex]\((5.5, 4.3)\)[/tex]

Other Questions