Question
Solve the following equations. Check your result in case.
0.18(5x - 4) = 0.5x + 0.8
0.18(5x - 4) = 0.5x + 0.8
✓
Answer
$0.18(5\text{x} - 4) = 0.5\text{x} + 0.8$
$\frac{18}{100}(5\text{x}-4)=\frac{5}{10}\text{x}+\frac{8}{10}$
$\frac{18(5\text{x}-4)=50\text{x}+80}{100}$
$\Rightarrow90\text{x}-72=50\text{x}+80$
$\Rightarrow90\text{x}-50\text{x}=80+72$
$\Rightarrow40\text{x}=152$
$\Rightarrow\text{x}=\frac{152}{40}=\frac{38}{10}=3.8$
$\therefore\text{x}=3.8$
Check:
L.H.S. = 0.18(5x - 4)
= 0.18(5 × 3.8 - 4)
= 0.18(19.0 - 4)
= 0.18 × 15
= 2.70
= 2.7
R.H.S. = 0.5x + 0.8
= 0.5 × 3.8 + 0.8
= 1.90 + 0.8
= 1.9 + 0.8
= 2.7
$\because$ L.H.S. = R.H.S.
Hence x = 3.8
$\frac{18}{100}(5\text{x}-4)=\frac{5}{10}\text{x}+\frac{8}{10}$
$\frac{18(5\text{x}-4)=50\text{x}+80}{100}$
$\Rightarrow90\text{x}-72=50\text{x}+80$
$\Rightarrow90\text{x}-50\text{x}=80+72$
$\Rightarrow40\text{x}=152$
$\Rightarrow\text{x}=\frac{152}{40}=\frac{38}{10}=3.8$
$\therefore\text{x}=3.8$
Check:
L.H.S. = 0.18(5x - 4)
= 0.18(5 × 3.8 - 4)
= 0.18(19.0 - 4)
= 0.18 × 15
= 2.70
= 2.7
R.H.S. = 0.5x + 0.8
= 0.5 × 3.8 + 0.8
= 1.90 + 0.8
= 1.9 + 0.8
= 2.7
$\because$ L.H.S. = R.H.S.
Hence x = 3.8
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