Answer:
[tex]n = 1230 - 30a[/tex]
Step-by-step explanation:
Given
[tex]3a + 0.1n = 123[/tex]
Required
Solve for n
[tex]3a + 0.1n = 123[/tex]
Subtract 3a from both sides
[tex]3a - 3a + 0.1n = 123 - 3a[/tex]
[tex]0.1n = 123 - 3a[/tex]
Divide through by 0.1
[tex]n = \frac{123 - 3a}{0.1}[/tex]
Split the fraction
[tex]n = \frac{123}{0.1} - \frac{3a}{0.1}[/tex]
[tex]n = 1230 - 30a[/tex]