Question

find the value of 77×83 by using formula

Answer 1

77×83= (80-3)×(80+3)
now (a-b)(a+b)=
$a ^{2} - b ^{2}$
therefore the answer is 80^2-3^2

6400-9=6391

Answer 2

Answer: The value of 77 x 83 is 6391

Step-by-step explanation:

We know that 77 x 83 can be written as (80-3)x(80+3)

Now as we know the algebraic property is  $(a+b)(a-b)= a^2 -b^2$

By using the mentioned property  we get

$77\times 83 = (80-3)(80+3) = 80^2-3^2 =6400-9 =6391$

Hence, the value of 77 x 83 is 6391