Okay, so, what you want to do is to factor out a GCF (greatest common factor). In this case, it would be y
y^2 - 4y = 0 <--- factor out GCF
y (y- 4) = 0 <---- separate into two equations
y= 0
y= 0
y- 4= 0 <--- add 4 to both sides to isolate y
y= 4
So your solutions are y= 0, 4. BUT!!!! Remember to ALWAYS, ALWAYS, ALWAYS check your solution for extraneous solutions because sometimes, the solutions will not satisfy the expression.
If the solution results in a false statement, then the answer is not a solution to the expression. If the solution results in a true statement, then the answer IS a solution to the equation.
Comments
Factor:
y² - 4y = 0
y(y - 4) = 0
y = 0 OR y = 4.
Okay, so, what you want to do is to factor out a GCF (greatest common factor). In this case, it would be y
y^2 - 4y = 0 <--- factor out GCF
y (y- 4) = 0 <---- separate into two equations
y= 0
y= 0
y- 4= 0 <--- add 4 to both sides to isolate y
y= 4
So your solutions are y= 0, 4. BUT!!!! Remember to ALWAYS, ALWAYS, ALWAYS check your solution for extraneous solutions because sometimes, the solutions will not satisfy the expression.
If the solution results in a false statement, then the answer is not a solution to the expression. If the solution results in a true statement, then the answer IS a solution to the equation.
Check y =0
(0)^2 - 4(0)= 0
0 = 0
True.
Check y=4
(4)^2 - 4(4)= 0
16 - 16 = 0
0 = 0
True.
So your answers are indeed y = 0,4
y ( y - 4 ) = 0
"basically since this is an equation of 1 variable, just 'factor' out a single y since there is a y in both terms, and leave the rest in parentheses."
answers:
y = 0
and
set y - 4 = 0 and solve for y
y = 4
so, the two solutions that satisfy this equation are: y = 0, and 4
verification:
(0)^2 - 4(0) = 0
0 - 0 = 0
(4)^2 - 4(4) = 0
16 - 16 = 0
Y^2 = 4Y. Easy answer: Y = 0 or 1. Just saying.
Of course, you could go with the hard answer, which is Y = 4. 4*4 = 4*4
-Bitchin Tri$tann
it can be factored in:: y (y - 4) = 0
so y=0 or y=4
y^2 -4y = 0
y(y-4) = 0
y=0, 4 check 0(0-4) ==> 0(4) = 0
4(4-4) = 4(0) = 0
y(y-4) = 0.
Solutions would be y = 0 and y = 4.
The GCF of the left side is y, so
y(y – 4) = 0
with solutions y = 0, 4
y(y - 4) = 0
y = 0 or y = 4