Question

The sum of two numbers is 31 and the difference of the same two numbers is 9. Find the LARGER of the 2 numbers.

A. 19
B. 12
C. 11
D. 20

Answer 1

20

Explanation:

let one number be X and the other Y

so that

X+Y=31

X-Y=9

by use of simultaneous.... X= 20 and Y is 11

Answer 2

1: x + y = 31

2: y - x = 9

1 rearranged for x: x = 31-y

2 rearranged for x: x = y-9

31-y = y-9

40 - y = y

40 = 2y

y = 20

Plug y in any equation to solve for x

x + 20 = 31

x = 11

20 is greater than 11

Your answer is D