Hello,
Work:
Equation;
[tex]n(17 + x) = 34x - r[/tex]
Use commutative property to reorder the terms.
[tex]34nx \times (17 + x) - r[/tex]
Distribute 34nx trough parenthesis.
[tex]578nx + 34nx^{2} - r \: \: \: \: \: \: \: \: result[/tex]
Hope this helps.
r3t40