Question

2х-7)(49+14х+4х^2)+343-4(2х-1)(2х+1)Найдите значение выражения при х= -0.5

Answer 1

(-1-7)*(49-7+4*0,5²)+343-4(-1-1)*(-1+1)

(-8)*(49-7+4*(1/2)²)+343-4*(-2)*0

(-8)*(49-7+4*1/4)+343-0

(-8)*(49-7+1)+343

(-8)*43+343

-344+343

-1

Answer 2

task/31614215

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* * *   (a-b)(a²+ab+b²) =a³ - b³  ; (a-b)(a+b) =a² - b²  * * *

(2x-7)(49+14x+4x²)+343-4(2x-1)(2x+1)  =

(2x-7)( (2x)²+2x*7+7²)+343 - 4( (2x)²-1²)  =

(2x)³ -7³ +343 -  4(4x²- 1) = 8x³ -343 +343 - 16x²+4 = 8x³ - 16x²+ 4 =

значение выражения при x= -0.5 = -1/2

8x³ - 16x²+ 4 = || x = - 1/2  ||  = 8*(-1/2)³ -16*(-1/2)² +4 = 8*(-1/8) - 16*1/4 + 4 =

-1 - 4 + 4  =   - 1

Answer 3

To find the value of the expression when x = -0.5, we simply substitute -0.5 in place of x and perform the calculations. Let's solve the expression step by step:

Expression: (2x - 7)(49 + 14x + 4x^2) + 343 - 4(2x - 1)(2x + 1)

Step 1: Substitute x = -0.5 in the expression. (2(-0.5) - 7)(49 + 14(-0.5) + 4(-0.5)^2) + 343 - 4(2(-0.5) - 1)(2(-0.5) + 1)

Step 2: Perform the calculations inside the parentheses and exponents. (-1 - 7)(49 - 7 + 4(0.25)) + 343 - 4(-1 - 1)(-1 + 1) (-8)(49 - 7 + 1) + 343 - 4(-2)(0) (-8)(43) + 343 - 0

Step 3: Calculate the products and the final result. -344 + 343 -1

So, the value of the expression when x = -0.5 is -1.