Number 10 pls​

How do you work out 21.3-8= show your working. plz

Lois and clark own a company that sells wagons. the amount they pay each of their sales employees (in dollars) is given by the expression 12h+30w12h+30w12, h, plus, 30, w where hhh is the number of hours worked and the number of wagons sold. what is the amount paid to an employee who works 666 hours and sells 333 wagons?

Keys to preventing a fall from a ladder include choosing the right ladder for the job and tying the top and bottom of the ladder to fixed paints. what else can you do to keep safe when using a ladder?