Answer:
x=-4/5
Step-by-step explanation:
8/20=x/-2
simplify 8/20 into 2/5
2/5=x/-2
cross product
5*x=-2*2
5x=-4
x=-4/5
Answer:

Step-by-step explanation:
As the numbers are only between 1 and 30
Total number of possible combinations = 30×30×30 = 27000
If there are 100 attempts then

∴ Probability someone can guess the correct combination given 100 attempts is 
Answer:
The patient would receive 1.05mg of the drug weekly.
Step-by-step explanation:
First step: How many mcg of the drug would the patient receive daily?
The problem states that he takes three doses of 50-mcg a day. So
1 dose - 50mcg
3 doses - x mcg
x = 50*3
x = 150 mcg.
He takes 150mcg of the drug a day.
Second step: How many mcg of the drug would the patient receive weekly?
A week has 7 days. He takes 150mcg of the drug a day. So:
1 day - 150mcg
7 days - x mcg
x = 150*7
x = 1050mcg
He takes 1050mcg of the drug a week.
Final step: Conversion of 1050 mcg to mg
Each mg has 1000 mcg. How many mg are there in 1050 mcg? So
1mg - 1000 mcg
xmg - 1050mcg
1000x = 1050

x = 1.05mg
The patient would receive 1.05mg of the drug weekly.
Answer:
595
Step-by-step explanation:
SOLUTION STEPS
(2.0×10−3)(3.5×10)
Multiply 2 and 10 to get 20.
(20−3)×3.5×10
Subtract 3 from 20 to get 17.
17×3.5×10
Multiply 17 and 3.5 to get 59.5.
59.5×10
Multiply 59.5 and 10 to get 595.
595
H=45d h stands for hours and 45d means 45 minutes per day