Question

15b-3(2b+5)+(-5b+7) если b=-0,8Найти значение выражения. ​

Answer 1

Ответ:-4.8

Пошаговое объяснение:

15b-3(2b+5)+(-5b+7) =

15b-6b-15-5b+7=

4b-8=

b=0.8

4*0.8-8=3.2-8 = -4.8

Answer 2

To find the value of the expression when b = -0.8, you simply need to substitute -0.8 for every occurrence of "b" in the expression and then perform the arithmetic operations.

Let's do that step by step:

Expression: 15b - 3(2b + 5) + (-5b + 7)

Now, replace b with -0.8:

15(-0.8) - 3(2(-0.8) + 5) + (-5(-0.8) + 7)

Next, perform the arithmetic operations:

15(-0.8) = -12 2(-0.8) = -1.6 -5(-0.8) = 4

So the expression becomes:

-12 - 3(-1.6 + 5) + (4 + 7)

Now, continue evaluating the expression:

-12 - 3(3.4) + 11

Now, calculate the multiplication and addition:

-12 - 10.2 + 11

Finally, perform the subtraction:

-12 + 11 - 10.2

Now, add the terms:

-1 - 10.2

Lastly, compute the result:

-11.2

The value of the expression when b = -0.8 is -11.2.