Question

The solution to #68 and #70

Answer 1

The trick is to write appropriate equations and then solve the system of equations you've created.

"sum of two numbers is -5:"  x + y = -5

"difference                   is  -1:"  x-y = -1

Add these two equations together.  This will cause y to drop out, and you will be left with an equation in x alone:

2x  = - 6, so x = -3.  Subst. -3 for x in either equation, above, and find the corresponding y value.

Then write your solution as (-3, y ) (write in your value for y).