Add: 5 (0.5k- 1) +2 (0.4- k). answer has to be decimal.
To calculate this expression (5(0.5k-1) + 2(0.4-k)), we need to distribute and simplify:
5(0.5k-1) + 2(0.4-k)
= 2.5k - 5 + 0.8 - 2k
= 0.5k - 4.2
Therefore, the simplified expression is 0.5k - 4.2.