Simplify 2/5n to 2n/5
2n/5 - 1 = -4
Add 1 to both sides
2n/5 = -4 + 1
Simplify -4 + 1 to -3
2n/5 = -3
Multiply both sides by 5
2n = -3 * 5
Simplify 3 * 5 to 15
2n = -15
Divide both sides by 2
n = -15/2
