6.4.3 Persamaan Linear, Praktis Berformat PT3

Soalan 7:
Selesaikan persamaan berikut:
$\begin{array}{l}\text{(a) }a-2=\frac{a}{5}\\ \text{(b) }\frac{b-3}{4}=\frac{2+b}{5}\end{array}$

Penyelesaian:
(a)
$\begin{array}{l}a-2=\frac{a}{5}\\ 5a-2=a\\ 4a=2\\ a=2\end{array}$

(b)
$\begin{array}{l}\frac{b-3}{4}=\frac{2+b}{5}\\ 5b-15=8+4b\\ 5b-4b=8+15\\ b=23\end{array}$

Soalan 8:
Selesaikan persamaan berikut:
$\begin{array}{l}\text{(a) }x=-24-x\\ \text{(b) }y+\frac{5}{4}\left(4-2y\right)=-4\end{array}$

Penyelesaian:
(a)
$\begin{array}{l}x=-24-x\\ 2x=-24\\ x=-12\end{array}$

(b)
$\begin{array}{l}y+\frac{5}{4}\left(4-2y\right)=-4\\ 4y+20-10y=-16\left(\times 4\right)\\ -6y=-16-20\\ -6y=-36\\ y=6\end{array}$

Soalan 9:
Selesaikan persamaan berikut:
$\begin{array}{l}\text{(a) }5p=8p-9\\ \text{(b) }3q=\frac{20-13q}{4}\end{array}$

Penyelesaian:
(a)
$\begin{array}{l}5p=8p-9\\ 5p-8p=-9\\ -3p=-9\\ p=3\end{array}$

(b)
$\begin{array}{l}3q=\frac{20-13q}{4}\\ 12q=20-13q\\ 12q+13q=20\\ 25q=20\\ q=\frac{4}{5}\end{array}$