The variable z is inversely proportional to x. when x is 6, z has the value 2.

what is the value of z when x = 13

Inverse variation is of the form yx=k, so we can say our equation is:

zx=k, we are given z=2 and x=6 so

2(6)=k

12=k, then our equation is:

zx=12, now when x=13

13z=12

z=12/13

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post