Question

Simplify(7x+11y)(7x-11y) and find the value for x=3and y=5

Answer 1

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Put x = 3, y = 5

= [7(3) + 11(5)][7(3) - 11(5)]

= ( 21 + 55 ) ( 21 - 55 )

= 76 × -34

= -2584

Answer 2

Substituting the value of x=3 and y=5, we get :-

==> (7×3+11×5)(7×3-11×5)

==> (21+55)(21-55)

==> 76 × -34

==> -2584

Answer ==> -2584.

While multiplying the integers, we need to keep something in mind :-

To multiply postive integers :-

Simply multiply them.

Example - 2×5 = 10

To multiply negative integers :-

●If we multiply negative Integers even number of times , we get a positive integer

Example = -4 × -5 = 20

●If we multiply negative Integers odd number of times we get a negative Integer.

Example = -4 × 5 = -20