Iam two numbers, the sum of my numbers is 100, the difference between my two numbers is 30,

Let the 2 numbers be x and y.
y = x + 30 ( as the difference between the two numbers is 30)
Sum of the two numbers = 100
=> x + y = 100
=> x + (x + 30) = 100                                            ( as y = x + 30 as shown above )
=> 2x = 70
=> x = 35
     y = x + 30 = 65
Hope I helped! you may comment here if you have any further doubts and i will answer them :)

Let the two numbers be x and y.

According to your question ;

x + y = 100
x - y = 30

Thus. x = y + 30

Substituting the value of x,

y + 30 + y = 100
2y + 30 = 100

y = 70 / 2 = 35

thus, y = 35

Substituting the value of y,

x + y = 100
x + 35 = 100
x = 100 -35 = 65
x = 65.

thus, the two numbers are 65 and 35.

Move the decimal behind it