In the given graph, P and Q are points such that PQ cuts off intercepts of 5 units and 3 units along the x-axis and y-axis respectively. Line RS is perpendicular to PQ and passes through the origin. Find the:
(a) coordinates of P and Q
(b) equation of line RS

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(a) Given,
PQ cuts off intercepts of 5 units and 3 units along the x-axis and y-axis respectively.
Thus,
Coordinates of P = (5, 0) and coordinates of Q = (0, -3).
Hence, coordinates of P = (5, 0) and coordinates of Q = (0, -3).
(b) By formula,
Slope (m) = $-\frac{y_2 - y_1}{x_2 - x_1}$
⇒ Slope of PQ = mPQ = $\frac{-3 - 0}{0 - 5} = \frac{-3}{-5} = \frac{3}{5}$.
We know that,
Product of slopes of perpendicular lines = -1.
⇒ Slope of RS × Slope of PQ = -1
⇒ Slope of RS × $\frac{3}{5}$ = -1
⇒ Slope of RS = $-\frac{5}{3}$.
By point-slope formula,
Equation of line : $y - y_{1} = m(x - x_{1})$
Since, slope of RS = $-\frac{5}{3}$ and it passes through the origin.
Equation of RS :
⇒ $y - 0 = -\frac{5}{3}(x - 0)$
⇒ y = $-\frac{5}{3}x$
⇒ 3y = -5x
⇒ 5x + 3y = 0.
Hence, the equation of line RS is 5x + 3y = 0.