Answer: Sure, here are the mathematical expressions for each phrase:
Let L be the original length, then the new length is L + 10 meters.
Let p be the original price of the shirt, then the cost after the discount is p - 0.3p = 0.7p.
Let p be the original price of the item, then 25% of the original price is 0.25p.
Let V be the original volume of water in the container, then the new volume is V + 5L.
Let r be the radius of a circle, then twice the product of x and the radius is 2xr.
Let X be Xavier's rate, then the rate that is two kph faster than Xavier's rate is X + 2 kph.
Explanation: