![\bf 400,000,000\implies 4\times 10^8 \\\\[-0.35em] ~\dotfill\\\\ \cfrac{\textit{desktop users}}{\textit{mobile users}}\qquad \qquad \cfrac{1.2\times 10^9}{4\times 10^8}\implies \cfrac{12\times 10^8}{4\times 10^8}\implies \cfrac{12}{4}\times\cfrac{10^8}{10^8}\implies \cfrac{3}{1}](https://tex.z-dn.net/?f=%5Cbf%20400%2C000%2C000%5Cimplies%204%5Ctimes%2010%5E8%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20%5Ccfrac%7B%5Ctextit%7Bdesktop%20users%7D%7D%7B%5Ctextit%7Bmobile%20users%7D%7D%5Cqquad%20%5Cqquad%20%5Ccfrac%7B1.2%5Ctimes%2010%5E9%7D%7B4%5Ctimes%2010%5E8%7D%5Cimplies%20%5Ccfrac%7B12%5Ctimes%2010%5E8%7D%7B4%5Ctimes%2010%5E8%7D%5Cimplies%20%5Ccfrac%7B12%7D%7B4%7D%5Ctimes%5Ccfrac%7B10%5E8%7D%7B10%5E8%7D%5Cimplies%20%5Ccfrac%7B3%7D%7B1%7D)
3 : 1, or 3 to 1, thus 3 times as many.
To do the first question, simplify the equation, putting like terms together, by adding and subtracting to do this.
Then looking at the equation that you solved for, look and see if there are any other equations that are related in some way to the original solved equation.
Pay close attention to the positive and negative signs.
