Answer:

Step-by-step explanation:
In order to add or subtract numbers in scientific notation, the powers of ten must have the same exponent. In this caes the diameter of an average human body cell is a power of -4 and the diameter of a plant cell is a power of -3. In order to add them, we can move the decimal over for the body cell diameter:

Add the two values: 
AngleA= angle D
5x+2=87
5x=85
X=17
180-87-42=51
Angle C= angle F
3y=51
Y=17
The answer would be A :))) hope you have a great day!
The answer is 227/25, first you add and subtract the similars (14-8+3 = 9). 9+8% is the new equation, 8/100 to get rid of a percentage, now it’s 9+8/100 = 227/25
The ratio is 4/5. They both can be reduced down by 9.