if you already know how to do one-step equations then you do the problem just like normal... but if you ae multiplying with decimals in this problem then i can show you how to do it! E.X 3.5 x 2.5= 875
so after you get the answer, to tell were the decimal on the answer goes you add the amount of numbers after the decimal together. so 3.5 has 1 number after the decimal point, and 2.5 has 1 number after the decimal point. so 1+1= 2 you start from the 8 and skip two numbers, and put the decimal point in between the 7 and 5. and your answer is 87.5
Hope That Helps! :)