Answer:
26
Step-by-step explanation:
Let the peter's number be represented x
Given that
1. if you subtract 19 from my number
writing it mathematically it will be x -19
2. multiply the difference by -3
it can be written as
since difference is x-19
multiplied the difference with -3
-3(x-19)
3. the result is -21
-3(x-19) = -21
dividing both side by -3
-3(x-19)/-3 = -21/-3
x-19 = 7
adding 19 both sides
x-19 + 19 = 7 + 19
x = 26
Thus, peter's number is 26.
