20 POINTS Set the two sides equal to each other and solve for x!

① -2x + 81 = 61

② 9x - 58 = 5

③ 21 + 10x = 3x + 28

④ 9x - 42 = 2x

(I already put them in the correct forms based on each images But here's the images anyways, just in case.)

1. x = 10  2. x = 7  3. x = 1  4. x = 6

Explanation:

1. -2x + 81 = 61 (Subtract 81 from 61)

  -2x = -20 (Divide)

   x = 10

2. 9x - 58 = 5 (Add 58 to 5)

   9x  = 63 (Divide)

   x = 7

3. 21 +10x = 3x + 28 (Rearrange expression)

   21 - 28 = 3x - 10x (Combine like terms)

   -7 = -7x (Divide)

    x = 1

4. 9x - 42 = 2x (Rearrange)

   9x - 2x = 42 (Combine like terms)

   7x = 42 (Divide)

   x = 6

answer: 1722

step-by-step explanation:

given: the mass of saturn=

the mass of mercury=

the number of times the mass of saturn is greater than the mass of mercury

hence, the mass of saturn is 1722 times greater than the mass of mercury.