Problem 4 algebra help needed

Question

Humberto had $1700 in a savings account to use for spending money during his summer trip for mexico he was careful and spent only $175 each week.

A) write a linear equation in slope intercept form that describes the amount of money Humberto had remaining in his account x weeks after he began his trip.

B) How much money did he have left after 6 weeks?

C) How many weeks did Humberto travel In Mexico if he had $125 left at the end of his trip?(use algebra to solve this and show you work)

Answer 1

Hi Angeles,

Remember: Slope-intercept form is y= mx + b

1. The value of b is always your starting amount. In this case it is $1700. On a graph, this would be your y-intercept.
2. The value of x is going to represent the number of weeks Humberto is on his vacation. This is also called the independent variable. (Y is the dependent variable because its value depends on the value of x)
3. Lastly, -175 is "m," also called slope or the rate of change. The number is negative because he is spending, or losing, this much money each week, so it gets subtracted from his account.

So, the slope intercept form would be y = -175x + 1700

To calculate how much he has left after 6 weeks on vacation, go ahead and plug in 6 for the value of "x," and then solve.

To answer question C, I would start again with the equation (y = -175x + 1700), but plug in $125 for "y" since that is the amount remaining after an unknown number of weeks of vacation. When you solve and find "x" you will know how many weeks he travelled.

I hope that helps!