2 step equations

Question

Ella swims in a pool four times a week at perfect clubs pool she swims the same number of laps on Monday Wednesday and Friday and 15 laps on Saturday she swims a total of 51 laps each week how many laps did she do on Monday

Answer 1

From the given facts, you should subtract Saturday's 15 laps from the weekly total of 51, so this gives you 36 laps total swum on the 3 days MWF.  Dividing by 3, you see that she swam 12 laps on Monday (and also on Wed & Fri).