Which is the approximate solution to the system [tex]y = 0.5x + 3.5[/tex] and [tex]y = -\frac{2}{3}x + \frac{1}{3}[/tex] shown on the graph?

A. [tex](-2.7, 2.1)[/tex]
B. [tex](-2.1, 2.7)[/tex]
C. [tex](2.1, 2.7)[/tex]
D. [tex](2.7, 2.1)[/tex]



Answer :

To find the approximate solution to the system of linear equations given by [tex]\( y = 0.5x + 3.5 \)[/tex] and [tex]\( y = -\frac{2}{3}x + \frac{1}{3} \)[/tex], we need to determine the point of intersection of these two lines.

### Step-by-Step Solution:

1. Set the equations equal to each other to find the x-coordinate of the intersection:
[tex]\[ 0.5x + 3.5 = -\frac{2}{3}x + \frac{1}{3} \][/tex]

2. Combine like terms by adding [tex]\(\frac{2}{3}x\)[/tex] to both sides:
[tex]\[ 0.5x + \frac{2}{3}x + 3.5 = \frac{1}{3} \][/tex]

3. Convert 0.5 to a fraction to make the arithmetic easier:
[tex]\[ \frac{1}{2}x + \frac{2}{3}x = \frac{1}{3} - 3.5 \][/tex]

4. Find a common denominator for the fractions:
[tex]\[ \frac{3}{6}x + \frac{4}{6}x = \frac{1}{3} - \frac{10.5}{3} \][/tex]
Simplify the left side:
[tex]\[ \frac{7}{6}x = \frac{1}{3} - \frac{10.5}{3} \][/tex]

5. Simplify the right side:
[tex]\[ \frac{1}{3} - \frac{10.5}{3} = \frac{1 - 10.5}{3} = \frac{-9.5}{3} \][/tex]

6. Express [tex]\(\frac{-9.5}{3}\)[/tex] as a single fraction:
[tex]\[ \frac{7}{6}x = \frac{-9.5}{3} \][/tex]

7. Solve for [tex]\( x \)[/tex] by multiplying both sides by the reciprocal of [tex]\(\frac{7}{6}\)[/tex]:
[tex]\[ x = \frac{-9.5}{3} \times \frac{6}{7} \][/tex]
Simplify this:
[tex]\[ x = \frac{-9.5 \times 6}{3 \times 7} = \frac{-57}{21} = -\frac{57}{21} = -2.7 \][/tex]

8. Substitute [tex]\( x = -2.7 \)[/tex] back into one of the original equations to find the y-coordinate:
Use [tex]\( y = 0.5x + 3.5 \)[/tex]:
[tex]\[ y = 0.5 \times (-2.7) + 3.5 \][/tex]
Simplify this:
[tex]\[ y = -1.35 + 3.5 = 2.15 \][/tex]
Approximate to one decimal place:
[tex]\[ y \approx 2.1 \][/tex]

### Conclusion

The approximate solution to the system is [tex]\((-2.7, 2.1)\)[/tex].

### Therefore, the answer is: [tex]\((-2.7, 2.1)\)[/tex].