Question

(7x-9x)(7x+9y)-49x² при x=2;y=0,01​

Answer 1

(7x-9y)(7x+9y)-49x²=

=49x²-81y²-49y²=

=-81y²

х=2 у=0,01

-81у²= -81•0,01²= -81•0,0001= -0,0081

Answer 2

Ответ:

Объяснение:

49х^2-64у^2-49х^2=-64у^2. Если у=0,01, то -64•0,01^2=-0,0064. Ответ: -0,0064.

Answer 3

To evaluate the expression (7x - 9x)(7x + 9y) - 49x² at x = 2 and y = 0.01, we substitute the given values into the expression and perform the calculations.

Let's start by substituting the values of x and y into the expression:

(7(2) - 9(2))(7(2) + 9(0.01)) - 49(2)²

Simplifying further:

(-2)(14 + 0.09) - 49(4)

Calculating inside the parentheses:

(-2)(14.09) - 49(4)

Now, perform the multiplications:

-28.18 - 196

Finally, subtract the two values:

-28.18 - 196 = -224.18

Therefore, when x = 2 and y = 0.01, the expression (7x - 9x)(7x + 9y) - 49x² evaluates to -224.18.