Answer:
The numbers are -3 and 18 .
Explanation:
Let us assume that first number be x.
Let us assume that the second number be y.
As given
A first number plus twice a second number is 12 .
Than the equation becomes
x + 2y = 12
As given
Twice the first number plus the second totals 33.
2x + y = 33
Than the two equations are
x + 2y = 12
2x + y = 33
Multiply x + 2y = 12 by 2 and subtracted from 2x + y = 33
2x - 2x + y - 4y = 33 - 24
-3y = 9
y = - 3
Put in the equation x + 2y = 12
x + 2 ×-3 = 12
x - 6 = 12
x = 12 + 6
x = 18
Therefore the numbers are -3 and 18 .