Answer:
Step-by-step explanation:
h=-5t²+135
when t=3 s
h=-5(3)²+135=-45+135=90 m
Hi, I think what you need to do is multiply 21 x 4 x 1/3. If you need help multiplying there’s a helpful website called Calculator Soup that is very helpful.
Answer:

Step-by-step explanation:

Answer:
Step-by-step explanation:
7.8+3.5(6.8)-1.5
7.8+23.8-1.5
31.6-1.5
30.1