The subtraction theorem states that for all real numbers,

and

,

.
(To subtract, we can add the inverse.)
Thus, we can have the these two equivalent expressions.
Answer:
3/10
Step-by-step explanation:
2/5 + x = 7/10
x = 7/10 - 2/5
x = 7/10 - 4/10
x = 3/10
The answer is 210 hope this helps
Speed= distance divided by time. The answer is 30, and im assuming miles per hour. Hope this helps