Answer:
p = 3/10
Step-by-step explanation:
p + 2/5 = 7/10
we need to isolate p, so to do that we subtract 2/5 from both sides. since 2/5 - 2/5 is 0, you can eliminate 2/5 and isolate p
p + 2/5 = 7/10
- 2/5 - 2/5
p = 7/10 - 2/5
p = 7/10 - 4/10 = 3/10 (changed 2/5 into 4/10 by multiplying both numerator and denominator by 2)