Question
Simplify the expression
9a−4−2a2
Evaluate
(4−a)(2a−1)
Apply the distributive property
4×2a−4×1−a×2a−(−a×1)
Multiply the numbers
8a−4×1−a×2a−(−a×1)
Any expression multiplied by 1 remains the same
8a−4−a×2a−(−a×1)
Multiply the terms
More Steps

Evaluate
−a×2a
Multiply the numbers
−2a×a
Multiply the terms
−2a2
8a−4−2a2−(−a×1)
Any expression multiplied by 1 remains the same
8a−4−2a2−(−a)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
8a−4−2a2+a
Solution
More Steps

Evaluate
8a+a
Collect like terms by calculating the sum or difference of their coefficients
(8+1)a
Add the numbers
9a
9a−4−2a2
Show Solution

Find the roots
a1=21,a2=4
Alternative Form
a1=0.5,a2=4
Evaluate
(4−a)(2a−1)
To find the roots of the expression,set the expression equal to 0
(4−a)(2a−1)=0
Separate the equation into 2 possible cases
4−a=02a−1=0
Solve the equation
More Steps

Evaluate
4−a=0
Move the constant to the right-hand side and change its sign
−a=0−4
Removing 0 doesn't change the value,so remove it from the expression
−a=−4
Change the signs on both sides of the equation
a=4
a=42a−1=0
Solve the equation
More Steps

Evaluate
2a−1=0
Move the constant to the right-hand side and change its sign
2a=0+1
Removing 0 doesn't change the value,so remove it from the expression
2a=1
Divide both sides
22a=21
Divide the numbers
a=21
a=4a=21
Solution
a1=21,a2=4
Alternative Form
a1=0.5,a2=4
Show Solution
