The answer is 50. Simply add the numbers together arithmetically as you would for the problem two plus two. To check your work, a calculator is the best option.
205
20 + 12 + 32 + 20 + 30 + 72 = 186
30 or -10 if the 20 is negative.
-20
50 + 40 + 40 + 40 + 30 + 30 + 20 + 10 = 260
5x + 20 = 4x +30 5x - 4x = 30 - 20 x = 10
18 + 10 + 20 + 30 + 15 + 50= 143
a = 20
10 + 20 = 30
200
20 + 10 - 31 + 30 - 5 = 24
10 plus 20 plus 30plus 40 plus 50 equals 150 because 50 plus 40 equals 90 plus 30 =120+20= 140 then + 10 = 150