you can do ANYTHING to an equaiton as long as you do it to both sides
try to get place holder by itself
4.5b+9=90 minus 90 from both sides 4.5b+9-9=90-9 4.5b+0=81 4.5b=81 either divide both sides by 4.5 or double 4.5 to get rid of the decimal I will double double both sides 9b=162 divid both sides by 9 b=18
