Let's rewrite the expression as
So, if 
, you may divide both sides by 
, the equation becomes 
, and the only solution is 
, which means that this is not an identity (an indentity is tautologically true, no matter the value of x).
If instead 
, you are multiplying both sides by zero, so the equation becomes
So, it doesn't matter which value for x you choose, because you will always end up with 
, which is obviously always true.
Answer:
Her son is 10 years old.
Step-by-step explanation:
Let son be x
Ellie is 4x
In 5 years time: Her son = x + 5
Ellie = 4x + 5
Given that she will then be 3 times as old as her son: 4x + 5 = 3(x + 5)
Solve x: 4x + 5 = 3(x + 5) ,4x + 5 = 3x + 15
x = 10
Example
2^3 4^2
2×2×2=6 4×4=16
All you do is multiply the number by the exponent however many times the exponents is
