Algebra
Calculus
Trigonometry
Matrix
Question
Simplify the expression
21x2−42x
Evaluate
7(x−2)×3x
Multiply the terms
21(x−2)x
Multiply the terms
21x(x−2)
Apply the distributive property
21x×x−21x×2
Multiply the terms
21x2−21x×2
Solution
21x2−42x
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Find the roots
x1=0,x2=2
Evaluate
7(x−2)(3x)
To find the roots of the expression,set the expression equal to 0
7(x−2)(3x)=0
Multiply the terms
7(x−2)×3x=0
Multiply
More Steps
Multiply the terms
7(x−2)×3x
Multiply the terms
21(x−2)x
Multiply the terms
21x(x−2)
21x(x−2)=0
Elimination the left coefficient
x(x−2)=0
Separate the equation into 2 possible cases
x=0x−2=0
Solve the equation
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Evaluate
x−2=0
Move the constant to the right-hand side and change its sign
x=0+2
Removing 0 doesn't change the value,so remove it from the expression
x=2
x=0x=2
Solution
x1=0,x2=2
Show Solution