Subtract 10 times the sum of 2.33 and 18.67 from 150. What's the difference?

Subtract 10 times the sum of 2.33 and 18.67 from 150. What's the difference?

Subtract 10 times the sum of 2.33 and 18.67 from solution 150
=150-（2.33+18.67）*10
=150-21*10
=150-210
=-60

(18:33:10 on the 23rd)
Given the power of X -- the power of y = - 1, x + y = 1 / 2, find X -- y
 

x^2-y^2=-1
(x+y)(x-y)=-1
Substituting x + y = 1 / 2 into (x + y) (X-Y) = - 1, we get the following result:
x-y=-2

2,3,5,10,18,33,61, --, fill in the blanks according to the rule

Each number is the sum of the first three numbers. For example, 18 is equal to 3 5 10, 61 is equal to 10 18 33, so the next number is equal to 18 33, 61 is equal to 112