ISEE Upper Level Math : How to find the solution to an equation

Study concepts, example questions & explanations for ISEE Upper Level Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #61 : How To Find The Solution To An Equation

Solve the set of equations:

Possible Answers:

Correct answer:

Explanation:

Solve the first equation for :

Substitute into the second equation:

PLug this back into our new equation for :

Example Question #62 : How To Find The Solution To An Equation

Solve the set of equations:

Possible Answers:

Correct answer:

Explanation:

Solve the first equation for :

Substitute into the second equation:

Plug this back into our new equation for :

 

Example Question #63 : How To Find The Solution To An Equation

Solve the set of equations:

Possible Answers:

Correct answer:

Explanation:

Solve the first equation for :

Substitute this expression into the second equation:

Now we should solve the following set of equations for and :

Solve the second equation for :

Substitute  into the first equation:

 

 

We also know , so plug in our new values:

 

Example Question #64 : How To Find The Solution To An Equation

Solve the set of equations:

Possible Answers:

Correct answer:

Explanation:

Solve the first equation for :

Substitute this expression into the second equation:

Now we should solve the following set of equations:

We can sum up both equations to get:

Substitute this new value into the second equation of the second set i.e. :

We had , so now:

 

 

 

 

Example Question #61 : How To Find The Solution To An Equation

Solve for .

Possible Answers:

Correct answer:

Explanation:

First we need to rewrite the problem by combining the like terms:

Now add to both sides:

 

Example Question #62 : How To Find The Solution To An Equation

Solve for .

Possible Answers:

Correct answer:

Explanation:

First we should combine like terms.


 

Example Question #63 : How To Find The Solution To An Equation

Solve for .

Possible Answers:

Correct answer:

Explanation:

First we need to rewrite the right side fractions as equivalent fractions with the same denominators. The easiest denominator to use is the product of the denominators (). However, the best denominator to use is the least common denominator, which is the least common multiple of the denominators ( in this case).

 

 

Example Question #2 : Word Problems

John sells cloths. His monthly salary is dollars plus a commission of  dollars for each cloth sold. If he sells cloths this month, how much money does he make in dollars?

Possible Answers:

Correct answer:

Explanation:

In order to find how much he makes from selling the cloths, we first multiply the number of cloths sold by dollars.

dollars

Now we add his monthly salary:

 dollars

Example Question #2 : Word Problems

Tom works in a mall and sells shoes. His monthly salary is  dollars plus a commission of dollars for every pair of shoes that he sells. How many pairs of shoes must he sell to earn dollars per month.

Possible Answers:

Correct answer:

Explanation:

Let number of pairs of shoes.

Then we can set up the following equation:

Now we solve the equation for :

Example Question #26 : Percentages

A college has students. If percent of them are boys, how many girls are there?

 

Possible Answers:

Correct answer:

Explanation:

percent of the students are boys, so percent of the students are girls.

Let = number of girls.

Then we can set up the following proportion:

 

 

 

Learning Tools by Varsity Tutors