2007-07-07 07:00:00 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
81r² - 36rs + 4s² = 0
8xr² - 18rs - 18rs + 4s² = 0
9r(9r - 2s) - 2s(9r - 2s) = 0
(9r - 2s)(9r - 2s) = 0
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2007-07-07 07:10:55 · answer #1 · answered by SAMUEL D 7 · 1⤊ 0⤋
(a - b)^2 = a^2 - 2ab + b^2
so 81r^2 - 36rs + 4s^2
= (9r)^2 - 2 x 9r x 2s + (2s)^2
= (9r - 2s)^2
2007-07-07 14:06:46 · answer #2 · answered by Anonymous · 0⤊ 0⤋
81r^2 - 36rs + 4s^2
(9r*9r) - 2*9r*2s + (2s*2s)
(9r)^2 - 2*9r*2s + (2s)^2
Note: a^2 - 2ab + b^2 = (a - b)^2
here a = 9r, b = 2s so
(9r- 2s)^2 is the final answer
2007-07-07 14:09:09 · answer #3 · answered by kannan r 2 · 0⤊ 0⤋
You can notice that this is a perfect square trinomial in the form a^2 - 2ab + b^2. To factor this, you must put it in the form (a-b)^2 or in this case, (9r-2s)^2 = (9r-2s)(9r-2s)
2007-07-07 14:05:14 · answer #4 · answered by magixter 2 · 0⤊ 0⤋
(a-b)^2=a^2-2*ab+b^2
so,
(9r-2s)^2= 81r^2 - 36rs + 4s^2
2007-07-07 14:03:16 · answer #5 · answered by MeisəM 4 · 0⤊ 0⤋
81r² - 36rs + 4s²
= 81r² - 18rs - 18rs + 4s²
= 9r(9r - 2s) - 2s(9r - 2s) Now group the factors.
= (9r-2s)(9r - 2s)
= (9r - 2s)²
2007-07-07 14:12:11 · answer #6 · answered by Sparks 6 · 0⤊ 0⤋
81r^2 - 36rs + 4s^2
= 81r^2 - 18rs - 18rs + 4s^2
= 9r*(9r - 2s) - 2s*(9r - 2s)
= (9r-2s)*(9r - 2s)
= (9r - 2s)^2
2007-07-07 14:05:41 · answer #7 · answered by Nterprize 3 · 0⤊ 0⤋
its a perfect square
(9r-2s)^2
2007-07-07 14:04:10 · answer #8 · answered by olens 2 · 0⤊ 0⤋
perfect squares: (9r-2s)^2
2007-07-07 19:46:49 · answer #9 · answered by dr_no4458 4 · 0⤊ 0⤋
(9r - 2s)^2
2007-07-07 14:03:46 · answer #10 · answered by Anonymous · 0⤊ 0⤋