Answer:
- oscilloscope: $465
- multimeter: $109
Explanation:
You want the costs of an oscilloscope and a multimeter when the sum of their costs is $574, and the difference of their costs is $356.
Sum and difference
Let o and m represent the costs of the oscilloscope and multimeter, respectively. Then the costs can be described by ...
o +m = 574
o -m = 356
Solution
Adding these two equations gives ...
2o = (574+356) = 930
o = 465 . . . . . . . . . . . . divide by 2
Subtracting the second equation from the first gives ...
2m = 574 -356 = 218
m = 109 . . . . . . . . . . . . divide by 2
The oscilloscope costs $465; the multimeter costs $109.
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Additional comment
This is the generic solution to a "sum and difference" problem: the higher value is half the sum of the given numbers, and the lower value is half their difference.