Question

(7x-8)(7x+8)-7x(7x+8) при х=3,5

Answer 1

49x^2 - 64 - 49x^2 - 56x = - 56x - 64

x = 3,5
- 56*3,5 - 64 = - 260

Answer 2

(24.5-8)(24.5+8)-24.5(24.5+8)=16.5*32.5-600.25+196=536.25-600.25+196=132. Надеюсь помог)

Answer 3

To find the value of the expression (7x - 8)(7x + 8) - 7x(7x + 8) when x = 3.5, we simply need to substitute the value of x into the expression and then evaluate it.

Let's do the calculation step by step:

Step 1: Replace x with 3.5 in the expression (7x - 8)(7x + 8):

(7 * 3.5 - 8)(7 * 3.5 + 8)

Step 2: Simplify the expression inside the first set of parentheses:

(24.5 - 8)(7 * 3.5 + 8)

Step 3: Simplify the expression inside the second set of parentheses:

(16.5)(24.5 + 8)

Step 4: Perform the multiplication:

16.5 * 32.5

Step 5: Calculate the final result:

536.25

So, when x = 3.5, the value of the expression (7x - 8)(7x + 8) - 7x(7x + 8) is 536.25.