factor:
-20x^2 + 5y^2
is it
-20x^2 + 5y^2
= -5(4x^2-y^2)
no the answer is
-5(2x-y)(2x+y)
^is that right??
Yes !!! You got it.
even the -1 * -1 = + 1 part
thankyou!
To factor the expression -20x^2 + 5y^2, we first look for any common factors.
The expression -20x^2 + 5y^2 has a common factor of 5, so we can factor it out:
-20x^2 + 5y^2 = 5(-4x^2 + y^2)
Now, let's focus on the expression inside the parentheses: -4x^2 + y^2. This is a difference of squares because we have the square of a binomial (y^2) minus the square of another binomial (2x^2).
The formula for factoring a difference of squares is: a^2 - b^2 = (a + b)(a - b).
In our case, a = y and b = 2x. So we can rewrite the expression as:
-4x^2 + y^2 = (y + 2x)(y - 2x)
Therefore, the factored form of -20x^2 + 5y^2 is:
-20x^2 + 5y^2 = 5(y + 2x)(y - 2x)