Question 1040483: I am having trouble with this question: "What is the product of (y+2)(y-8)? The answers available are
y^2+6y-16 , y^2-6y-16 , y^2-6y+16 , y^2+6y+16 . Please explain how you got the correct answer, thank you so much in advance , Emily.
Found 3 solutions by josgarithmetic, Theo, MathTherapy:
Answer by josgarithmetic(39617)   (Show Source):
Answer by Theo(13342)  (Show Source):
You can put this solution on YOUR website! all you need to do is multiply the factors together.
you would use the distributive law of multiplication.
that law says:
a * (b + c) =
(a*b) + (a*c)
that law also says:
(a + b) * (c + d) =
(a * (c + d)) + (b * (c + d)) =
(a*c) + (a*d) + (b*c) + (b*d).
in other words, every term in the multiplier needs to multiply every term in the multiplicand exactly one time.
this works for any number of terms.
a more complex example would be:
(a + b + c) * (d + e + f) =
(a * (d + e + f)) + (b * (d + e + f)) + (c * (d + e + f)) =
(a*d) + (a*e) + (a*f) + (b*d) + (b*e) + (b*f) + (c*d) + (c*e) + (c*f)
in your problem:
start with (y+2) * (y-8)
this becomes (y*(y-8)) + (2*(y-8))
which becomes (y*y) - (y*8) + (2*y) - (2*8)
simplify this to get y^2 - 8y + 2y - 16
combine like terms to get y^2 - 6y - 16
i believe that is one of your selections.
Answer by MathTherapy(10551)  (Show Source):
You can put this solution on YOUR website!
I am having trouble with this question: "What is the product of (y+2)(y-8)? The answers available are
y^2+6y-16 , y^2-6y-16 , y^2-6y+16 , y^2+6y+16 . Please explain how you got the correct answer, thank you so much in advance , Emily.
Apply the FOIL method of distribution
(y + 2)(y - 8)
y(y - 8) + 2(y - 8)
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