The sum of two numbers is 15. The difference of the same two numbers is 8.

Use algebra to work out the numbers.

7

Step-by-step explanation:

15-8=7 this is how you answer it

11.5 and 3.5

Step-by-step explanation:

a+b=15

a-b=8

equating them we get,

2a=23

a=11.5

placing value of b in a-b=8

11.5-b=8

b=3.5

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.