you begin with $25 in a savings account and $50 in the checking account. Each week you deposit $5 into savings and $10 into checking. After how many weeks is the amount in checking twice the amount in savings? write and solve an equation.
To find the answer to this question, you simple have to find the answer to the following sequence. 105=50+50=100 55=25+25=50 Answer: 5 weeks
You begin with:
After first week:
After second week:
After third week:
After fourth week:
After fifth week:
You can see that after fifth week the amount in checking is twice the amount in savings.
Let x be the number of weeks, then the equation is:
25+5x=50,
5x=50-25,
5x=25,
x=25:5,
x=5.
Answer: after 5th week.