Answer:

Step-by-step explanation:
difference of a number and 9 means to subtract

twice that means multiply by 2

at least is greater than or equal to

Answer:
a. -7 + 3
b. draw 7 negatives + 7 positives
Step-by-step explanation:
The surface area will increase by a factor of 49/16
Answer:
150cm
Step-by-step explanation:
0.4*100-5=35
(35+40)*2=150