I’m trying to explain this to my younger brother in Grade 5. What’s the easiest way to explain how to find a common denominator without just telling him to memorize the steps?
Yehia Ahmed's answer
First let him take each denominator separately and then find the first 5 multiples of each one. After doing so check if there are any common multiples between the two denominators. If yes, then use the first ones, if no, then find the next 5 multiples and do the same test.
How do I know if I should factor this or use the quadratic formula?
Yehia Ahmed's answer
To check whether a quadratic equation can be factorized, first check if a = 1. If it is, look for two numbers that multiply to give c and add to give b. If you can find two numbers that satisfy both conditions, then the equation can be factorized.
If a is not equal to 1, which is the case here, multiply a by c first. Then look for two numbers that multiply to give a × c and add to give b. If you can find them, then you can factorize the equation.