A N S W E R :
For simplifying an expression, there are some rules about the order in which the calculations should be performed. The order of rules is called BODMAS. Each letter in this word stands for an operation.
- B = Brackets
- O = Off
- D = Division
- M = mass
- A = addition
- S = substraction
→ -2.5(-3 + 4n + 8) = 0
→ 7.5 + (-10n) + (-20) = 0
→ 7.5 - 10n - 20 = 0
→ -10n - 20 + 7.5 = 0
→ -10n - 12.5 = 0
→ -10n = 12.5
→ n = 12.5 ÷ -10
→ n = -1.25
