Which pair of integers has sum equal to -5 ?
-9 and 15
14 and -9
-20 and 15
5 and -5
Answers
Answer:
Wyzant
INTEGERS
Logan M. asked • 09/19/14
Two integers have a difference of 6 and a sum of -18. What are the two integers?
Two integers have a difference of 6 and a sum of -18. What are the two integers?
Follow3
Add comment
More
2 Answers By Expert Tutors
By:
Best
Damazo T. answered • 09/19/14
TUTOR 4.9 (147)
Math Tutoring by 15 year veteran math teacher/Real cheap! :)
SEE TUTORS LIKE THIS
Let x be the smaller integer
Let y be the larger integer
Their difference is -6. Difference implies subtraction. So, x-y=6
Their sum is -18. Sum means addition. Thus, x+y= -18
so, we have what is called a System of Linear Equations. There are many different ways to solve a system of linear equations. You can use the Elimination Method, the Substitution Method, graph them, use matrices.
I am going to use the Elimination Method. We have:
x - y = 6
x + y = -18
add the top equation to the bottom equation.
x+ x= 2x , (-y)+y= 0 and. 6 + (-18)= -12
So, 2x= -12
x= -6
To find y, plug in -6 for x in either x-y=6 or x+y= -18. I am going to choose the latter, x+y= -18. Substituting -6 for x, we have:
(-6)+y = -18
+6. +6 Adding six to both sides
0 + y = (-12)
final answer : y= -12 , x= -6