Factor completely
49x^2-9
2007-11-24 04:24:39 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
49x^2 - 9
49x^2 = (7x)^2
9 = (3)^2
Difference of two squares
a^2 - b^2 = (a + b)(a - b)
(7x + 3)(7x - 3) {factored form}
2007-11-24 04:29:17 · answer #1 · answered by Anonymous · 1⤊ 0⤋
49x^2 -9=0
49x^2=9, x^2= 9/49, x= square root of 9/49.
x= +or- 3/7.
2007-11-24 06:04:19 · answer #2 · answered by Sasi Kumar 4 · 0⤊ 0⤋
As the others say, this is (7+3) x (7-3) = 10 x 4.
To factorise 10 x 4, we get (2 x 5) x (2 x 2) = 2 x 2 x 2 x 5.
2007-11-24 05:36:10 · answer #3 · answered by za 7 · 0⤊ 0⤋
The answer is C. You can see by inspection that in the format (a+b)(c+d) - the FOIL process - your b and d will multiply to -81, so 9 and -9 should stand out in your mind. It should also be apparent that the a and c will multiply to 49x², so 7x and 7x should stand out in your mind. After that, the rest kind of falls into place. You can check the answer by going backwards. (7x+9)(7x-9) F-First 7x*7x=49x² O-Outter 7x*-9=-63 I-Inner 9*7x=63x L-Last 9*-9=-81 Now add them all together: 49x²+63x-63x-81 49x²-81 Yep!
2016-05-25 05:15:29 · answer #4 · answered by milagro 3 · 0⤊ 0⤋
Remember a^2-b^2=(a+b)(a-b)
=(7x+3)(7x-3)
2007-11-24 04:27:24 · answer #5 · answered by SaintPretz59 4 · 0⤊ 0⤋
49x² -9 = (7x +3)(7x-3)
2007-11-24 04:27:59 · answer #6 · answered by ernanepl 3 · 0⤊ 0⤋
49x^2-9=
(7x+3)(7x-3)
2007-11-24 04:34:09 · answer #7 · answered by Dr. Nick 6 · 0⤊ 0⤋
49x 2
2017-01-15 07:18:15 · answer #8 · answered by ? 4 · 0⤊ 0⤋
this is a difference of squares:
(7x-3)(7x+3)
2007-11-24 04:32:35 · answer #9 · answered by sayamiam 6 · 0⤊ 0⤋
(7x+3)(7x-3)
2007-11-24 04:44:25 · answer #10 · answered by Anonymous · 0⤊ 0⤋