Math Olympiad | Learn how to find the value of 7^(x-y) | Math Olympiad Preparation

Today I will teach you tips and tricks to solve the given olympiad math question in a simple and easy way. Learn how to prepare for Math Olympiad fast!

Need help with solving this Math Olympiad Question? You're in the right place!

I have over 20 years of experience teaching Mathematics at American schools, colleges, and universities. Learn more about me at

Math Olympiad | Learn how to find the value of 7^(x-y) | Math Olympiad Preparation

#OlympiadMathematics #OlympiadPreparation #CollegeEntranceExam
#OlympiadMathematicalQuestion #HowToSolveOlympiadQuestion #MathOlympiadQuestion #MathOlympiadQuestions #OlympiadQuestion #Olympiad #AlgebraReview #Algebra #Mathematics #Math #Maths #CompetitiveExams
#MathOlympiadPreparation #OlympiadMathematicsCompetition #MathOlympics #SolveSystemofEquations #RadicalEquation #RadicalEquations
#blackpenredpen #solveTheCubicEquation #CubicEquation #ExponentialEquation #ExponentialEquations #LinearEquation #OlympiadMathematics #QuadraticEquation
#QuadraticEquations #RationalEquation #RationalEquations

How to solve Olympiad Mathematical Question
How to prepare for Math Olympiad
How to Solve Olympiad Question
How to Solve international math olympiad questions
international math olympiad questions and solutions
international math olympiad questions and answers
olympiad mathematics competition
blackpenredpen
math olympics
olympiad exam
olympiad exam sample papers
math olympiad sample questions
math olympiada
British Math Olympiad
olympics math
olympics mathematics
olympics math activities
olympics math competition
Math Olympiad Training
How to win the International Math Olympiad | Po-Shen Loh and Lex Fridman
Po-Shen Loh and Lex Fridman
Number Theory
There is a ridiculously easy way to solve this Olympiad qualifier problem
This U.S. Olympiad Coach Has a Unique Approach to Math
The Map of Mathematics
mathcounts
math at work
exponential equation
system of equations
solve system of equations
solve the equation
solve the cubic equation
cubic equation
pre math
Poh Shen Loh
Olympiad Mathematics
Learn how to find the value of 7^(x-y)
Rational Equations
Rational Equation
Radical Equation
Radical Equations
Competitive exams

Subscribe Now as the ultimate shots of Math doses are on their way to fill your minds with the knowledge and wisdom once again.

[jorghimvenerablebosstein]

I find it fascinating that the final answer is just an integer! Cool vid!

[vitalistiknius]

Even easier:
(7a+b)/(a+7b)=13/3
7a+b=13/3a+91/3b
(7-13/3)a=(91/3-1)b
((7-13/3)/(91/3-1))(a/b)=1
a/b=(91-3)/(21-13)=11

[giuseppemalaguti]

11....divido entrambe le equazioni per 7^y...ottengo 2 equazioni la cui prima parte è uguale (a meno di una costante 13/3)...eguaglio queste 2 parti la cui incognita é proprio 7^(x-y)..

[luisalfredonarvaeznarvaez]

Maravilloso Profesor, Maravilloso
Gracias por sus enseñanzas

[zplusacademy]

250 likes ❤️❤️❤️❤️🙏🙏🙏🙏🙏🙏🙏 extremely beautiful sharing ❤️🙏🙏🙏

[guyhoghton]

The √7 factor on the right hand sides is inconsequential because the solution depends on the ratio of the two equations. It could have been √71 or π or anything (except 0) as long as it was the same in both equations; it cancels itself out.
The equations can be rewritten:
7ʸ(7.7ˣ⁻ʸ + 1) = 13√7 ... ➀
7ˣ(7.7ʸ⁻ˣ + 1) = 3√7 ... ②
Dividing ② by ➀:
7ˣ(7.7ʸ⁻ˣ + 1) / 7ʸ(7.7ˣ⁻ʸ + 1) = 3/13 ( the √7 factor has gone)
Putting u = 7ˣ⁻ʸ :
u(7/u + 1)/(7u + 1) = 3/13
⇒ (7 + u)/(7u + 1) = 3/13
⇒ 91+ 13u = 21u + 3
⇒ 8u = 88
⇒ u = 11

[davidfromstow]

Yet another brilliant video - thank you

[alexniklas]

Solved without: a= 7^x; b=7^y.
7^(x-y)= 11