Find 0.15% of 43 cookies

43/x=100/0.15
(43/x)*x=(100/0.15)*x       - we multiply both sides of the equation by x
43=666.666666667*x       - we divide both sides of the equation by (666.666666667) to get x
43/666.666666667=x 
0.0645=x 
x=0.0645

now we have: 
0.15% of 43=0.0645

A. p = 2(l + w)p/2 - l = ww = p/2 - l b. while isolating the variable w in the equation, i first divided both sides by 2 and then i subtracted l from both sides. i hope this .