Question

Номер 727 1)20-2r=r-1​

Answer 1

Ответ:

20-2r=r-1

-2r-r=-1-20

-3r=-21

r=7

Answer 2

To solve the equation 20 - 2r = r - 1, we can follow these steps:

1. Start by simplifying both sides of the equation: 20 - 2r = r - 1

   Subtract r from both sides: 20 - 2r - r = -1

   Simplify the left side by combining like terms: 20 - 3r = -1

2. Move the constant term to the right side by adding 3r to both sides: 20 - 3r + 3r = -1 + 3r

   Simplify the left side by canceling out the -3r and +3r terms: 20 = -1 + 3r

3. Move the constant term to the left side by subtracting -1 from both sides: 20 - (-1) = -1 + 3r - (-1)

   Simplify the left side by performing the subtraction: 20 + 1 = 3r + 1

   Combine the terms on the left side: 21 = 3r + 1

4. Move the constant term to the right side by subtracting 1 from both sides: 21 - 1 = 3r + 1 - 1

   Simplify the left side by performing the subtraction: 20 = 3r

5. Finally, solve for r by dividing both sides by 3: 20/3 = 3r/3

   Simplify the right side by canceling out the 3's: 20/3 = r

So, the solution to the equation 20 - 2r = r - 1 is r = 20/3.