Question

Решить: -х(х+7)+(х+5)(х-5)При х=3/7​

Answer 1

Ответ:

Пошаговое объяснение:

-х(х+7)+(х+5)(х-5)=-х^2-7х+х^2-25=-7х-25

-7*3/7-25=-3-25=-28

Answer 2

To solve the expression for the given value of x, which is x = 3/7, we simply substitute this value into the expression and perform the calculations step by step:

Expression: -x(x + 7) + (x + 5)(x - 5)

Substitute x = 3/7:

= -(3/7)(3/7 + 7) + (3/7 + 5)(3/7 - 5)

Now, let's simplify the expression:

= -(3/7)(3/7 + 49/7) + (22/7)(-32/7)

= -(3/7)(52/7) - 704/49

= -156/49 - 704/49

Now, we combine the fractions:

= (-156 - 704) / 49

= -860 / 49

So, the value of the expression when x = 3/7 is -860/49.