Kill two birds with one stone

Kill two birds with one stone
killing two birds with one stone means to achieve two goals or complete two tasks with a single action.

Examples: 
1 - By starting a vegetable garden, Jake teaches his children about gardening and saves money on groceries — killing two birds with one stone.
2 - Mia combined her business trip with a vacation, exploring a new city while attending meetings — killing two birds with one stone.