Please help...I am supposed to perform the indicated operation.
2007-11-24 12:14:53 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
[10]
(3m-4)(3m+4)
=(3m)^2-(4)^2
=9m^2-16
2007-11-24 12:19:12 · answer #1 · answered by alpha 7 · 0⤊ 2⤋
(3m-4)(3m+4) ... Start with the given expression
Remember, when you FOIL an expression, you follow this procedure:
Multiply the First terms: (3m)*(3m)=9m^2 ...
Multiply the Outer terms: (3m)*(4)=12m ...
Multiply the Inner terms: (-4)*(3m)=-12m ...
Multiply the Last terms: (-4)*(4)=-16 ...
9m^2+12m-12m-16 ... Now collect every term to make a single expression
9m^2-16 ... Now combine like terms
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Answer:
So (3m-4)(3m+4) ... foils and simplifies to 9m^2-16
In other words, (3m-4)(3m+4)=9m^2-16
Notice how 9m^2-16 factors back to the original expression (3m-4)(3m+4) . So this verifies our answer.
2007-11-24 20:18:54 · answer #2 · answered by Jim 5 · 1⤊ 1⤋
Use the FOIL method.
First, Outter, Inner, Last.
So...
3m * 3m = 9m^2
3m * 4 = 12m
3m * -4 = 12m
-4 * 4 = -16
Which is equal to:
9m^2 + 12m - 12m -16
Then combine like terms:
(12m - 12m = 0)
Final answer:
9m^2 - 16
2007-11-24 20:20:01 · answer #3 · answered by Cleo 3 · 0⤊ 1⤋
First: use the Foil method...
(3m)(3m)+(3m)(4)+(-4)(3m)+(-4)(4)
==> 9m^2+12m +(-12m)+(-16)
==> 9m^2+12m - 12m -16
SEc: combine "like" terms (combine terms with the same letter)...
==> 9m^2 - 16
2007-11-24 20:40:46 · answer #4 · answered by ♪♥Annie♥♪ 6 · 0⤊ 1⤋
9m^2 - 16
2007-11-24 20:17:47 · answer #5 · answered by norman 7 · 0⤊ 1⤋
9m^2-16
2007-11-24 20:17:44 · answer #6 · answered by MollyMAM 6 · 0⤊ 1⤋
=(3m*3m)+(3m*4)+(-4*3m)+(-4*4)
=(9m^2)+(12m)+(-12m)+(-16)
=9m^2-16
2007-11-24 20:19:29 · answer #7 · answered by DUDE 2 · 0⤊ 1⤋