# Rate problem algebra mistakes

Due to the nature of the mathematics on this site it is best views in landscape mode. If your device is not in landscape mode many of the equations will run off the side of your device should be able to scroll to see them and some of the menu items will be cut off due to the narrow screen width. Algebra Errors The topics covered here are errors that students often make in doing algebra, and not just errors typically made in an algebra class. In fact, a few of the examples in this section will actually come from calculus.

View SourceShow About mbarugel: I'm rate problem algebra mistakes running OnlineMathAnswers. These problems usually go along the lines of: When working at the same time as Worker B, they can finish the job in 2 hours.

How long does it take for Worker B to finish the job if he works alone? Painter B works twice as fast as A. How long would it take to each of them to paint it if they worked alone? Pipe A delivers 1, litres per hour. When pipe A and B are both on, they can fill an empty pool in 4 hours. How many litres per hour can pipe B deliver?

Actually, they are quite simple once you know how to set up the appropiate equation or system of equations. I'll give you now the single most important formula that will help you solve these problems. Basic Formula Let's assume we have two workers pipes, machines, etc: Worker A can finish a job in X hours when working alone.

Worker B can finish a job in Y hours when working alone The number of hours they need to complete the job when they're both working at the same time is given by Once you're "armed" with this formula, solving these problems will be very easy.

We'll see a few examples below; but first, let me show where this formula comes from. Where does the formula come from? We started the problem with the following assumptions. There are two workers pipes, machines, etcA and B.

Worker A can finish a job in X hours when working alone; Worker B can finish the same job in Y hours when working alone.

## Intro to rates

That is, how many jobs can he complete in one hour? Clearly, if he takes X hours to complete a job, the he can complete jobs per hour.

If he needs 30 minutes 0. The same reasoning applies to worker B. What happens if they're working together? In this case we have to add their rate of work.

This is clearly wrong, as it would imply that they need more time when working together than when working by themselves. So we need to sum their rate of work.

If A completes jobs per hour, and B completes jobs per hours, then, when working together, they can complete jobs per hour. Finally, given that they can complete jobs per hour; then how many hours do they take to complete one job? This is simply the inverse of the above formula.

So they can complete 1 job in hours.

What does it mean that a worker works N times faster than another one?[beautiful math coming please be patient] $\displaystyle\frac{10\text{ kg}}{{\text{ in}}^3}$, read as “ten kilograms per cubic inch” A rate is a mathematical expression, and like all types of mathematical expressions.

Algebra Mistakes. I have gathered here a collection of mistakes that are pretty easy to make. Try to avoid these! Math video on how to apply the step function to a real world problem such as taxi rates given a base rate and additional fees based on mileage.

Problem 3. Common Algebra II Mistakes. 6 videos. Concept. 2 min. Problem 1. 1 min. Problem 2. 1 min. Problem 3. 1 min. Problem 4. Step Functions - Problem 3. Carl Horowitz. Carl Horowitz. At the same time, kids can learn to use their arithmetic on this type of problem, and for a lot of kids this can be productive as they’re getting the hang of algebra.

If a kid is comfortable with arithmetic, they could think of this as 21 – BLA = 9. There are really three kinds of “bad” notation that people often use with fractions that can lead to errors in work. The first is using a “/” to denote a fraction, for instance 2/3.

In this case there really isn’t a problem with using a “/”, but what about 2/3$$x$$? This can be either of the two following fractions.

Three Common Algebra Mistakes You MUST Avoid Whether it is a calculus class or a first algebra class, I have seen students at every level and every natural ability make these mistakes. Why would so many fall into these traps?

Algebra (Practice Problems)