Are you asking:
What two numbers have a sum of 15 and a difference of 7 ?
Some quick mental arithmetic would tell you they are 11 and 4
algebraic solution:
x+y = 15
x-y = 7
add them
2x = 22
x = 11, sub into the first to get y = 4
what is the sum of 15 but the difference of 7
1 answer
1 answer