The amount of x is in weeks, while the 4 and the 25 are in days. There are 7 days in a week, so we would have to multiply the number of weeks by 7 to get how many days that would be. This amount of days, plus the 4 days, has to be able to equal 25. This gives you the equation:
7x+4=25
Steps to solve:
1. Subtract 4 from both sides to get the variable and its coefficient alone: 7x = 21.
2. Divide both sides by 7 to get x alone: x=3.
If we verify the equation by putting 3 in for x, we get 7(3)+4=25, then 21+4=25, and finally 25=25. 25 IS equal to 25, so this statement is true and 3 is correct for the value of x.
Therefore, the answers are:
a) 7x+4=25
b) x=3
