Question

1)10x+7=8x-9 2)20-3x=2x-45 3)2,7+1,9x=2x+1,5 4)13/18x+13=7/12x+8 решите пожайлуста(

Answer 1

1) 10x+7=8x-9. 10x-8x=-9-7. 2x=-16. x=-8. 2) 20-3x=2x-45. 20+45=2x+3x. 65=5x. x=13. 3) 2,7+1,9x=2x+1,5. 2,7-1,5=2x-1,9x. 1,2=0,1x. x=12. 4) 13/18x+13=7/12x+8. 13/18x-7/12x=8-13. Общей знаменатель 36. 26/36x-21/36x=-5. 5/36x=-5. 5=-5•36x. -1=36x. x=-1/36 P.S- на счёт 4) не уверенна.

Answer 2

Solution:

To solve the given equations, let's solve them one by one:

Equation 1: 10x + 7 = 8x - 9

To solve this equation, we need to isolate the variable x on one side of the equation. We can do this by subtracting 8x from both sides and subtracting 7 from both sides:

10x + 7 - 8x = 8x - 9 - 8x

Simplifying the equation:

2x + 7 = -9

Next, we can isolate the variable x by subtracting 7 from both sides:

2x + 7 - 7 = -9 - 7

Simplifying further:

2x = -16

Finally, we can solve for x by dividing both sides of the equation by 2:

x = -8

Equation 2: 20 - 3x = 2x - 45

To solve this equation, we need to isolate the variable x on one side of the equation. We can do this by adding 3x to both sides and adding 45 to both sides:

20 - 3x + 3x = 2x - 45 + 3x

Simplifying the equation:

20 = 5x - 45

Next, we can isolate the variable x by adding 45 to both sides:

20 + 45 = 5x - 45 + 45

Simplifying further:

65 = 5x

Finally, we can solve for x by dividing both sides of the equation by 5:

x = 13

Equation 3: 2.7 + 1.9x = 2x + 1.5

To solve this equation, we need to isolate the variable x on one side of the equation. We can do this by subtracting 2x from both sides and subtracting 2.7 from both sides:

2.7 + 1.9x - 2x = 2x - 2x + 1.5 - 2.7

Simplifying the equation:

1.9x - 2x = -1.2

Next, we can combine like terms:

-0.1x = -1.2

Finally, we can solve for x by dividing both sides of the equation by -0.1:

x = 12

Equation 4: (13/18)x + 13 = (7/12)x + 8

To solve this equation, we need to isolate the variable x on one side of the equation. We can do this by subtracting (7/12)x from both sides and subtracting 13 from both sides:

(13/18)x + 13 - (7/12)x = (7/12)x - (7/12)x + 8 - 13

Simplifying the equation:

(13/18)x - (7/12)x = -5

Next, we need to find a common denominator for the fractions:

(13/18)x - (7/12)x = -5

Multiplying the first fraction by 2/2 and the second fraction by 3/3:

(26/36)x - (21/36)x = -5

Combining like terms:

(5/36)x = -5

Finally, we can solve for x by multiplying both sides of the equation by the reciprocal of (5/36), which is (36/5):

x = -5 * (36/5)

Simplifying further:

x = -36

Therefore, the solutions to the given equations are: - x = -8 - x = 13 - x = 12 - x = -36