Question

1) -3*(2b-5)-1,8 при b=1,5 2)-5,1+9*(-с-4)при с=(-2) для 6 классов

Answer 1

Сначала упростить выражение...

Answer 2

To solve these expressions, simply substitute the given values for the variables and perform the arithmetic operations. Let's go step by step:

1. -3*(2b - 5) - 1.8 when b = 1.5

Replace b with 1.5 in the expression:

-3*(2*1.5 - 5) - 1.8

Perform the operations inside the parentheses first:

-3*(3 - 5) - 1.8

Now, perform the remaining operations:

-3*(-2) - 1.8

Multiply -3 by -2:

6 - 1.8

Finally, subtract 1.8 from 6:

6 - 1.8 = 4.2

So, the value of the expression is 4.2 when b = 1.5.

2. -5.1 + 9*(-с - 4) when с = -2

Replace с with -2 in the expression:

-5.1 + 9*(-(-2) - 4)

Perform the operations inside the parentheses first:

-5.1 + 9*(2 - 4)

Now, perform the remaining operations:

-5.1 + 9*(-2)

Multiply 9 by -2:

-5.1 - 18

Finally, subtract 18 from -5.1:

-5.1 - 18 = -23.1

So, the value of the expression is -23.1 when с = -2.