I think i know the answer but i dont know why
i need it done in like a step by step process so i can know how to do these kind myself thanks so much!
(x-5)squared
is the answer x squared-10x+25
if so, why?
2007-10-01 17:46:08 · 9 answers · asked by Angelica 1 in Science & Mathematics ➔ Mathematics
yes that's the answer.
(x-5)^2 = (x - 5) (x - 5)
Now use FOIL - First Outer Inner Last
First is x * x
Outer is x * (-5)
Inner is (-5) * x
Last is (-5) * (-5)
x^2 - 5x - 5x + 25
x^2 -10x + 25
2007-10-01 17:53:48 · answer #1 · answered by Justin M 4 · 0⤊ 0⤋
Use the FOIL method. FOIL stands for first, inner, outer, last.
(x-5)^2 This is how we have to write (x-5)squared here because we can't make the little 2 up high for the exponent in Yahoo Answers. Still write it the normal way in your homework.
(x-5)(x-5)
Each parenthesis has an x first, so for FOIL we have x times x or x^2.
The outer terms are the x of the first parenthesis and the -5 of the second parenthesis. x times -5 = -5x
The inner terms are the -5 of the first parenthesis and the x of the second parenthesis. -5 times x = -5x
The last terms are -5 in the first parenthesis and -5 in the second parenthesis. -5 times -5 = 25
Put all those together,
first, inner, outer, last
x^2 - 5x - 5x + 25 = x^2 -10x + 25 when we combine the -5x and -5x into -10x.
2007-10-02 00:56:51 · answer #2 · answered by ecolink 7 · 0⤊ 0⤋
x^2 -10x +25
Mutilplay the outside numbers and add the middle product to the outer product
So x times x = x^ and -5 times -5 = 25
-5 times x is -5x and again makes -10x
2007-10-02 00:50:38 · answer #3 · answered by ignoramus 7 · 0⤊ 0⤋
yep, there's a formula for this
(a-b)^2=a^2+b^2-2ab
sustitute values, x^2+25-2*5*x
x^2+25-10x or x^2-10x+25
this is much quicker than using the FOIL method but it will still work either way
2007-10-02 00:57:03 · answer #4 · answered by mylostpets 2 · 0⤊ 0⤋
(x-5)^2 = (x-5)(x-5)
Using distributive law,
x^2-5x-5x+25 = x^2-10x+25
Just remember the formula (a+b)^2 = a^2+2ab+b^2 because chances are in a test u will not have enough time to do it step by step
2007-10-02 00:52:24 · answer #5 · answered by Achillezz 2 · 0⤊ 0⤋
(x-5)(x-5)
FOIL first inside outside last
x*x-5x-5x+25=x^2-10x+25
2007-10-02 00:51:46 · answer #6 · answered by allmine227 2 · 0⤊ 0⤋
(x-5)^2 is basically (x-5)(x-5)
there's a method called foil method where you do distribution.
so, (x)(x-5) = x^2-5x [i got the x from the first (x-5)]
then, -5(x-5) = -5x+25 [i got the -5 from the first (x-5)]
you add the two expressions and you end up with
x^2-10x+25
Get it?
2007-10-02 01:00:45 · answer #7 · answered by jebm3892 2 · 0⤊ 0⤋
here is the general property... a^2 = a x a
(x-5)^2
= (x-5)(x-5) <-- expand this
= x^2 - 5x -5x + 25
= x^2 - 10x + 25
2007-10-02 00:49:17 · answer #8 · answered by Andy T 2 · 0⤊ 0⤋
just the FOIL method. First, Outside,Inside,Last. (x-5)(x-5)
2007-10-02 00:51:38 · answer #9 · answered by Edward S 2 · 0⤊ 0⤋