Question

Two numbers have a sum of 7. When the smaller number is subtracted from twice the larger number, the result is 20. Which of the following is the largest number?:

(1): 9
(2): 11
(3): 12
(4): 15

Answer 1

(4): 15
That is the largest

Answer 2

The answer is 9.
according to the condition it is possible to make up a system of two equations (if to suppose '"' - the larger number and the 's' - is the smaller one):
1. 'two numbers have a sum of 7' means stI=7;
2. 'When the smaller number is subtracted from twice the larger number, the result is 20' means 2*1-5=20.
3. the system of two equations is:
^ $+l=7
12141=20 => 19=03
4. the larger number is 9.