Answer:
x=-3
Step-by-step explanation:
Since f(x) also means y, we are looking for a point where y=3
When x=-3, we see that y reaches 3
Therefore, the answer is x=-3
Answer:
t > 1380
Step-by-step explanation:
Subtract 7200 from both sides
10t + 7200 - 7200 > 21000 - 7200
Simplify
10t > 13800
Divide both sides by 10
10t/10 > 13800/10
Simplify
t > 1380
Check picture for working out