Would someone mind giving me a hand with this one! Thank you so much!
(15x - 5y) (17x -21y) Mulitply
2007-10-14 18:56:52 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
5(3x-y)(17x-21y)=
5(51x^2-63xy-17xy+21y^2)=
5(51x^2-80xy+21y^2)=
255x^2-400xy+105y^2
2007-10-14 19:04:17 · answer #1 · answered by sisi 3 · 0⤊ 0⤋
Just use the FOIL method (First, Outer, Inner, Last)
(15x - 5y) (17x -21y)
First (these are the terms that are first in each pair of parentheses):
15x * 17x = 255x²
Outer (the two terms on the outside):
15x * -21y = -315xy
Inner (the two terms on the inside):
-5y * 17x = -85xy
Last (the two terms that come last in each parenthesis):
-5y * -21y = 105y²
Now put them all together:
255x² - 315xy - 85xy + 105y²
But notice how outer and inner products are both xy terms, so combine them:
255x² - 400xy + 105y²
There you go... successfully multiplied.
2007-10-15 02:03:26 · answer #2 · answered by Puzzling 7 · 0⤊ 0⤋
= (15x - 5y) (17x - 21y)
= 255x^2 - 315xy - 85xy + 105y^2
= 255x^2 + 105y^2 - 400xy
Answer: 255x^2 + 105y^2 - 400xy
2007-10-15 04:01:23 · answer #3 · answered by Jun Agruda 7 · 2⤊ 0⤋
=255x^2 - 85xy - 315xy + 105y^2
=255x^2 - 400xy + 105y^2
simplifies to:
5(51x^2 - 80xy * 21y^2)
2007-10-15 02:02:00 · answer #4 · answered by kiwi25 3 · 0⤊ 0⤋
255 x ² - 315 xy - 85 xy + 105 y ²
255 x ² - 400 xy + 105 y ²
2007-10-15 08:44:47 · answer #5 · answered by Como 7 · 0⤊ 0⤋
=255x^2 -315xy -85xy +105y^2
= 255x^2 -400xy +105y^2
2007-10-15 02:03:22 · answer #6 · answered by skibz26 4 · 0⤊ 0⤋