Solve the system of equations:

[tex]\[
\left\{
\begin{array}{c}
\frac{x + y}{7} = \frac{x}{2} \\
\frac{3}{2} x + \frac{2}{5} y = 5
\end{array}
\right.
\][/tex]



Answer :

Let's solve the system of equations step by step.

Step 1: Write down the equations

We have the following system of equations:
[tex]\[ \frac{x + y}{7} = \frac{x}{2} \][/tex]
[tex]\[ \frac{3}{2}x + \frac{2}{5}y = 5 \][/tex]

Step 2: Clear fractions from the first equation

Multiply both sides of the first equation by 14 (the least common multiple of 7 and 2) to eliminate the fractions:
[tex]\[ 14 \cdot \frac{x + y}{7} = 14 \cdot \frac{x}{2} \][/tex]

This simplifies to:
[tex]\[ 2(x + y) = 7x \][/tex]

Distribute:
[tex]\[ 2x + 2y = 7x \][/tex]

Isolate [tex]\( y \)[/tex]:
[tex]\[ 2y = 7x - 2x \][/tex]
[tex]\[ 2y = 5x \][/tex]
[tex]\[ y = \frac{5}{2}x \][/tex]

Step 3: Substitute [tex]\( y \)[/tex] into the second equation

Now substitute [tex]\( y = \frac{5}{2}x \)[/tex] into the second equation:
[tex]\[ \frac{3}{2}x + \frac{2}{5}\left(\frac{5}{2}x\right) = 5 \][/tex]

Simplify the terms:
[tex]\[ \frac{3}{2}x + \frac{2}{5} \cdot \frac{5}{2}x = 5 \][/tex]
[tex]\[ \frac{3}{2}x + x = 5 \][/tex]

Combine the [tex]\( x \)[/tex] terms:
[tex]\[ \frac{5}{2}x = 5 \][/tex]

Multiply both sides by [tex]\( \frac{2}{5} \)[/tex] to solve for [tex]\( x \)[/tex]:
[tex]\[ x = 2 \][/tex]

Step 4: Find [tex]\( y \)[/tex]

Use the value of [tex]\( x \)[/tex] to find [tex]\( y \)[/tex]:
[tex]\[ y = \frac{5}{2}x \][/tex]
[tex]\[ y = \frac{5}{2} \cdot 2 \][/tex]
[tex]\[ y = 5 \][/tex]

So, the solution to the system of equations is:
[tex]\[ (x, y) = (2, 5) \][/tex]