Menu

Always True

Part of the Fundamentals section of Coddy's Algebra journey. Lesson 44 of 61.

The opposite can happen too. Take the equation 2(x+1)=2x+22\left(x+1\right) = 2x+2. Distribute the left side, and both sides become 2x+22x+2. Subtract 2x2x from both sides:

2=22 = 2

What is left is a true statement with no xx in it. A true statement means the original equation is true for every value of xx. Try x=0x = 0, x=7x = 7 or x=−3x = -3, and both sides always agree. An equation like this is called an identity, and its solution is all numbers.

When the unknown cancels out, look at the statement that is left. If it is false, the equation has no solution. If it is true, every number is a solution. Both of these are complete answers.

challenge icon

Challenge

Medium

Solve 3(x−2)=3x−63\left(x-2\right) = 3x-6. Distribute first, then compare the two sides.

Try it yourself

3(x−2)=3x−63\left(x-2\right) = 3x-6

Get xx alone

All lessons in Fundamentals