ALgebra
posted by Robert on .
Indicate and explain the logical error in the following set of algebraic expressions
Let a=b
square both sides to get a^2=b^2
a^2=b*b
Since a=b, then a^2=a*b
Subtract b^2 from both sides a^2b^2=a*bb^2
Factor both sides: (a+b)(ab)=b(ab)
Divide both sides by (ab)
(a+b)=b
Since a=b
b+b=b or
2b=b
Divide by b

You said " Divide both sides by (ab) " , but a = b
so you are dividing by zero, which is a nono in math .