SOLUTION: Find the value of two numbers if their sum is 70 and their difference is 36.

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Question 1112920: Find the value of two numbers if their sum is 70 and their difference is 36.
Found 2 solutions by ankor@dixie-net.com, greenestamps:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Find the value of two numbers if their sum is 70
a + b = 70
and their difference is 36.
a - b = 36
:
Use elimination on these two equations
a + b = 70
a - b = 16
------------Addition eliminates b, find a
2a + 0 = 86
a = 86/2
a = 43
Find b
43 + b = 70
b = 70 - 43
b = 27
:
:
Check
43 - 27 = 16

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


(1) By logical reasoning....

Think of the two numbers on a number line. If you start at the larger number and add the smaller, you end up at 70; if you start at the larger and subtract the smaller, you end up at 36. Logical analysis tells you the larger number is halfway between 36 and 70.

larger number = %2836%2B70%29%2F2+=+106%2F2+=+53
smaller number = 70-53+=+17

Answer: the two numbers are 53 and 17.

(2) algebraically....

x%2By+=+70
x-y+=+36
2x+=+106 (add the two equations)
x+=+53
53%2By+=+70
y+=+17