Question

-2n + 0.4(30 + 10n) = 0.6(15n - 20) - 4

Explanation:

Step1: Expand both sides

$-2n + 0.4\times30 + 0.4\times10n = 0.6\times15n - 0.6\times20 - 4$
$-2n + 12 + 4n = 9n - 12 - 4$

Step2: Simplify each side

$2n + 12 = 9n - 16$

Step3: Isolate n terms

$12 + 16 = 9n - 2n$

Step4: Solve for n

$28 = 7n$
$n = \frac{28}{7}$

Answer:

$n = 4$