Question

The value of (3y+7)²- (3y-7)²​

Answer 1

Answer:

84y

Step-by-step explanation:

$(3y + 7) {}^{2} - (3y - 7) {}^{2}$

=4×3y×7

=84y

Answer 2

Step-by-step explanation:

(3y+7)²- (3y-7)²

[9y²+49+2(3y)(7)]-[9y²+49-2(3y)(7)]

(9y²+49+42y)-(9y²+49-42y)

9y²+49+42y-9y²-49+42y

84y