Algebra
Calculus
Trigonometry
Matrix
Question
Factor the expression
(y−5)(y+4)
Evaluate
y2−y−20
Rewrite the expression
y2+(4−5)y−20
Calculate
y2+4y−5y−20
Rewrite the expression
y×y+y×4−5y−5×4
Factor out y from the expression
y(y+4)−5y−5×4
Factor out −5 from the expression
y(y+4)−5(y+4)
Solution
(y−5)(y+4)
Show Solution
Find the roots
y1=−4,y2=5
Evaluate
y2−y−20
To find the roots of the expression,set the expression equal to 0
y2−y−20=0
Factor the expression
More Steps
Evaluate
y2−y−20
Rewrite the expression
y2+(4−5)y−20
Calculate
y2+4y−5y−20
Rewrite the expression
y×y+y×4−5y−5×4
Factor out y from the expression
y(y+4)−5y−5×4
Factor out −5 from the expression
y(y+4)−5(y+4)
Factor out y+4 from the expression
(y−5)(y+4)
(y−5)(y+4)=0
When the product of factors equals 0,at least one factor is 0
y−5=0y+4=0
Solve the equation for y
More Steps
Evaluate
y−5=0
Move the constant to the right-hand side and change its sign
y=0+5
Removing 0 doesn't change the value,so remove it from the expression
y=5
y=5y+4=0
Solve the equation for y
More Steps
Evaluate
y+4=0
Move the constant to the right-hand side and change its sign
y=0−4
Removing 0 doesn't change the value,so remove it from the expression
y=−4
y=5y=−4
Solution
y1=−4,y2=5
Show Solution