Question

1) -3×(2b-5)-1,8 при b=1,5 2) 6×(d-2 1/3)+17 при d=-0, 5

Answer 1

1) Ответ: 4,2  -6*1,5+13,2  (вроде так)
2)  6*(-0,5 -21/3) + 17 = 0   (вроде так)

Answer 2

1. To evaluate the expression -3×(2b-5)-1.8 when b=1.5, we substitute the value of b into the expression:

-3×(2(1.5)-5)-1.8

First, we simplify the expression within the parentheses:

-3×(3-5)-1.8

Next, we simplify the expression within the second set of parentheses:

-3×(-2)-1.8

Multiply -3 by -2:

6-1.8

Finally, subtract 1.8 from 6:

4.2

Therefore, when b=1.5, the expression -3×(2b-5)-1.8 evaluates to 4.2.

2. To evaluate the expression 6×(d-2 1/3)+17 when d=-0.5, we substitute the value of d into the expression:

6×((-0.5)-2 1/3)+17

First, we convert the mixed number 2 1/3 to an improper fraction:

2 1/3 = 7/3

Substituting d=-0.5:

6×((-0.5)-7/3)+17

Next, we simplify the expression within the parentheses:

6×(-0.5-7/3)+17

To simplify further, we need a common denominator for -0.5 and 7/3, which is 6:

6×((-0.5)×6/6-(7/3)×2/2)+17

This becomes:

6×(-3/6-14/6)+17

Now, we subtract the fractions within the parentheses:

6×(-17/6)+17

Multiply -17/6 by 6:

-17+17

Finally, subtract 17 from 17:

0

Therefore, when d=-0.5, the expression 6×(d-2 1/3)+17 evaluates to 0.