2021-I-04

17-10-202112-06-2023 app.cch No Comments

Ans: (a)

- 4 \leq x < 7

(b)

6

Consider the first inequality, we have
$\begin{array}{rcl} \frac{7 (x - 2)}{5} + 11 & > & 3 (x - 1) \\ 7 x - 14 + 55 & > & 15 x - 15 \\ - 8 x & > & - 56 \\ x & < & 7 \end{array}$

Consider the second inequality, we have

$\begin{array}{rcl} x + 4 & \geq & 0 \\ x & \geq & - 4 \end{array}$

Therefore, the overall solutions are $- 4 \leq x < 7$ .
There are $6$ positive integers satisfying the both inequalities.

2021, HKDSE-MATH, Paper 1 Inequality

Leave a Reply Cancel reply