Algebra
Calculus
Trigonometry
Matrix
Question
Simplify the expression
21x2−90x+24
Evaluate
(7x−2)(3x−12)
Apply the distributive property
7x×3x−7x×12−2×3x−(−2×12)
Multiply the terms
More Steps
Evaluate
7x×3x
Multiply the numbers
21x×x
Multiply the terms
21x2
21x2−7x×12−2×3x−(−2×12)
Multiply the numbers
21x2−84x−2×3x−(−2×12)
Multiply the numbers
21x2−84x−6x−(−2×12)
Multiply the numbers
21x2−84x−6x−(−24)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
21x2−84x−6x+24
Solution
More Steps
Evaluate
−84x−6x
Collect like terms by calculating the sum or difference of their coefficients
(−84−6)x
Subtract the numbers
−90x
21x2−90x+24
Show Solution
Factor the expression
3(7x−2)(x−4)
Evaluate
(7x−2)(3x−12)
Factor the expression
(7x−2)×3(x−4)
Solution
3(7x−2)(x−4)
Show Solution
Find the roots
x1=72,x2=4
Alternative Form
x1=0.2˙85714˙,x2=4
Evaluate
(7x−2)(3x−12)
To find the roots of the expression,set the expression equal to 0
(7x−2)(3x−12)=0
Separate the equation into 2 possible cases
7x−2=03x−12=0
Solve the equation
More Steps
Evaluate
7x−2=0
Move the constant to the right-hand side and change its sign
7x=0+2
Removing 0 doesn't change the value,so remove it from the expression
7x=2
Divide both sides
77x=72
Divide the numbers
x=72
x=723x−12=0
Solve the equation
More Steps
Evaluate
3x−12=0
Move the constant to the right-hand side and change its sign
3x=0+12
Removing 0 doesn't change the value,so remove it from the expression
3x=12
Divide both sides
33x=312
Divide the numbers
x=312
Divide the numbers
More Steps
Evaluate
312
Reduce the numbers
14
Calculate
4
x=4
x=72x=4
Solution
x1=72,x2=4
Alternative Form
x1=0.2˙85714˙,x2=4
Show Solution