SOLUTION: 2. Which of the following equations is linear? A. y = |x| B. y = 2x C. y = x2 Why?

Algebra ->  Linear-equations -> SOLUTION: 2. Which of the following equations is linear? A. y = |x| B. y = 2x C. y = x2 Why?       Log On


   

Question 1001961: 2. Which of the following equations is linear?
A. y = |x|
B. y = 2x
C. y = x2
Why?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

A linear equation is an equation for a straight+line.
answer is B. y+=+2x
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C2x%29+
other options are not linear equations because their graph is not a straight+line
see the graphs:
A. y+=+abs%28x%29
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2Cabs%28x%29%29+
C. y+=+x%5E2
+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2Cx%5E2%29+

the variables (like "x" or "y") in Linear Equations do NOT have:
exponents (like the 2 in x%5E2)
or square roots (like abs%28x%29=sqrt%28x%5E2%29, cube roots, etc