Question

1,2×(2х-9)-1,5×(5у+4) при х=45:у=6,3​

Answer 1

Ответ:

1) а) 16 б) -0,5 в) -2 г) 6 д) 0 е) Решений нет ж) 0 з) -5

2) а) -4 б) -1 в) -2 г) -6 д) 0 е) Решений нет ж) 0 з) 6,4

Пошаговое объяснение:

1) а) 2х-5=27

     2х=32

      х=16

б) -3+4у=-5

4у=-2

у=-0,5

в) 2х-1=4х+3

2х=-4

х=-2

г) 1/3у+2=-1/6у+5

1/3у+1/6у=3

3/6у=3

0,5у=3

у=6

д) 2х-(5х-6)=7+(х-1)

-3х+6=6+х

-4х=0

х=0

е) 3х-1=2х-(4-х)

3х-1=3х-4

3х-3х=-3

0х=-3?

Решений нет

ж) 2(х-3)=-3(х+2)

2х-6=-3х-6

5х=0

х=0

з) 2(х-5)-7(х+2)=1

2х-10-7х-14=1

-5х=25

х=-5

2) а) 4-3х=16

-3х=12

х=-4

б) 5у-7=-12

5у=-5

у=-1

в) 7х-1=2х-11

5х=-10

х=-2

г) 1/2у-3=-1/6у-7

4/6у=-4

у=-4/(4/6)

у=-6

д) 5х-(2х-9)=6+(х+3)

3х+9=9+х

2х=0

х=0

е) 7х-8=4х-(1-3х)

7х-8=7х-1

7х-7х=7

0х=7

Решений нет

ж) 3(х+4)=-4(х-3)

3х+12=-4х+12

7х=0

х=0

з) 3(х+2)-8(х-4)=-2

3х+6-8х+24=-2

-5х=-32

х=6,4

Answer 2

To evaluate the expression 1.2 × (2x - 9) - 1.5 × (5y + 4) when x = 45 and y = 6.3, we can substitute the given values into the expression and perform the calculations step by step.

Let's start with the substitution:

1.2 × (2(45) - 9) - 1.5 × (5(6.3) + 4)

Now we simplify the expressions inside the parentheses:

1.2 × (90 - 9) - 1.5 × (31.5 + 4)

Next, we perform the additions and subtractions:

1.2 × (81) - 1.5 × (35.5)

Now we multiply each term:

97.2 - 53.25

Finally, we subtract the second term from the first:

97.2 - 53.25 = 43.95

Therefore, when x = 45 and y = 6.3, the expression 1.2 × (2x - 9) - 1.5 × (5y + 4) evaluates to 43.95.