Question

4.
$5x + 3y = 5$
$5x + 2y = 10$

Explanation:

Step1: Label the equations

Let
$$5x + 3y = 5 \tag{1}$$
$$5x + 2y = 10 \tag{2}$$

Step2: Subtract eq(2) from eq(1)

Subtract to eliminate $5x$:
$$(5x + 3y) - (5x + 2y) = 5 - 10$$
$$y = -5$$

Step3: Substitute $y=-5$ into eq(1)

Solve for $x$:
$$5x + 3(-5) = 5$$
$$5x - 15 = 5$$
$$5x = 5 + 15$$
$$5x = 20$$
$$x = \frac{20}{5} = 4$$

Answer:

$x=4$, $y=-5$