Use substitution when either and x or y is given, for instance: x = 2y + 3 or y = 8x - 9.
Use elimination when a number from both equations can cancel each other out, for example:
2x + 3y = 19
-2x + 7y = 12
Hope this helps!

The sand we need to fill the cylinders is equal to the total volume of the six cylindrical posts .
Given terms ( common for each cylinder ) :
- height (h) = 4 ft
- radius. (r) = 0.5 ft

Since volume of each cylinder is equal, so total volume of six cylindrical post :
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Hi im Aleida and go to calculatorsoup on Safari or google and put gcf calculatorsoup hope this helps