Use doubles minus one to solve 8+7. Write the number sentence

Answer:8+8-1 = 15Step-by-step explanation:The doubles minus one is the technique to add two numbers which are consecutive.In this technique you add double the greatest number of the two consecutive and then subtract 1 from the result.Here we have equation 8+7.so doubling the greater number (8+8) or (8*2)  gives us 16.then subtracting 1 from it (16-1) gives us 15so 15 is our answer.