Question

I just wanna see if I'm doing this rite.
(7x -4)(7x+7)
28x 49x
Did I do that correct?

Answer 1

49x^2+49x-28x-28

Answer 2

(7x - 4)(7x + 7)
49x^2 + 49x - 28x - 28
49x^2 + 21x - 28

Answer 3

How did you get the 2

Answer 4

texaschic101

Answer 5

what 2 are you talking about ? Oh...you mean the 2 in 49x^2 ?
well...7x * 7x....you not only multiply the 7's, you have to multiply the x's also.
So 7x * 7x = 49x^2. Understand ?

Answer 6

you see, if you just have 7x * 7, that equals 49x, but if you have 7x * 7x, that equals 49x^2

Answer 7

Yes ok so did you multiply 7x +7x+7x to get the 21x -28

Answer 8

are you familiar with the FOIL method ?

Answer 9

No I'm just learning all this

Answer 10

FOIL stands for first, outside, inside, last
(7x - 4)(7x + 7)
First -- multiply first terms in each set...7x * 7x = 49x^2
Outside -- multiply outside terms in each set ...7x * 7 = 49x
Inside -- multiply inside terms in each set...-4 * 7x = -28x
Last -- multiply last terms in each set ...-4 * 7 = -28
now put it all together...
49x^2 + 49x - 28x - 28 -- combine like terms
49x^2 + 21x - 28

does that make it any clearer ?

Answer 11

Yes I'm going to rite this down. Thank you. Do you mind if I call on you again?