(a) \(\frac{x^{2} - y^{2}}{3x + 3y}\) \(\frac{(x + y)(x - y)}{3(x + y)}\) (Using difference of two squares) = \(\frac{x - y}{3}\) (b)(i) \(\sin 37 = \frac{/PS/}{15}\) \(/PS/ = 15 \times 0.6018\) = \(9.03 cm\) (ii) \(\cos 37 = \frac{/SK/}{15}\) \(/SK/ = 15 \times 0.7986\) = \(11.98 cm \) \(\approxeq 12.0 cm\) (iii) Area of the shaded portion = Area of rectangle PQRS - Area of triangle PSK. /SR/ = 2(/SK/) = 2(11.98) = 23.96 cm Area of rectangle PQRS = \(23.96 \times 9.03 \) = \(216.3588 cm^{2}\) Area of triangle PKS = \(\frac{1}{2} \times 11.98 \times 9.03\) = \(54.088 cm^{2}\) Area of shaded portion : \((216.3588 - 54.088)cm^{2}\) \(162.2708 cm^{2}\) \(\approxeq 162 cm^{2}\)