Answer:
1 + 1 + 2 + 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 + 7 + 8 + 8 + 9 + 9 + 10 + 10 - 90 = 20
Step-by-step explanation:
Answer:p=7
Step-by-step explanation:because 4 x 7 =28