b) Jika a ialah sebutan pertama dan \( r \) ialah nisbah sepunya bagi suatu janjang geometri, tunjukkan bahawa hasil tambah \( n \) sebutan pertama bagi janjang itu ialah If \( a \) is the first term and \( r \) is the common ratio of a geometric progression, show that the sum of the first \( n \) terms of the progression is \[ S_{n}=\frac{a\left(r^{n}-1\right)}{r-1} \] [3 markah]

GuidedPractice 1A. \( y=2 x+3 \) \( y=-2 x-5 \)

Risolvi le seques \( \frac{-x^{2}+7 x-12}{2 x^{2}-7 x+3} \geqslant 0 \)

\( \begin{array}{ll} & \text { Solve for } x: \\ 2.1 & (x-5)(x+3)=0 \\ 2.2 & 2^{x-1}=10-2^{x+1} \\ 2.3 & 5^{3 x-6}=125 \\ 2.4 & \frac{x^{2}-3}{2}=x\end{array} \)

3.1.2 The number pattern is quadratic and \( T_{4}=2+5 y \). 3.2 In a linear number pattern, the \( 19^{\text {th }} \) term is 40 and the \( 7^{\text {th }} \) term is 16 . Thus, determine the first two terms.

D) A student claimed that the largest integer of \( k \) for which the graph \( y=2 x^{2}-3 x+k-1 \) meets the \( x \)-axis is 2 . Verify this statement.