1). 8-9=-1
2). 9–9=18
3). 8–2+7=8+9
4). 8–2-7=8+5
Use the fraction addition formula.
Substitute the numbers into the formula.
a=5, b=1, c=1, d=7
Answer: David conducted (an observational study) because (it studies human behavior) and (the sample is not manuipulated).
Step-by-step explanation:
hope this helps! (:
Use Pythagoras’ theorem:
a^2+b^2=c^2
But we rearrange this formula to make it
c^2-a^2=b^2
So 25^2-15^2=b^2
625-225= b^2 = 400
You now need to find the square root of 400 to find the square root of b
sqrt of 400 is 20
So 20 is the missing length in this triangle
The reciprocal is the numer that you can multiply by the original number and get 1 as a resul
19 times what=1
divide boht sides by 19
whhat=1/19
therefor the reciprocal is just the fraction flipped
therefor if you had x/y the reciprocal would be y/x
so the answer is 1/19