Question
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^2-b^2=a*b-b^2
Factor both sides: (a+b)(a-b)=b(a-b)
Divide both sides by (a-b)
(a+b)=b
Since a=b
b+b=b or
2b=b
Divide by b
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^2-b^2=a*b-b^2
Factor both sides: (a+b)(a-b)=b(a-b)
Divide both sides by (a-b)
(a+b)=b
Since a=b
b+b=b or
2b=b
Divide by b
Answers
Reiny
You said " <b>Divide both sides by (a-b) </b>" , but a = b
so you are dividing by zero, which is a no-no in math .
so you are dividing by zero, which is a no-no in math .