Can you help please

top one:  (7b + 6)(7b - 6)

Step-by-step explanation:

the square root of 49b² = 7b

the square root of 36 = 6

you have to have one factor contain +6 and the other -6 so that, when you 'foil', the middle terms cancel out; and the 36 is negative

49b² - 42b +42b - 36  =  49b² - 36

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.