The third equation because whatever u plug int y u get an x value. The x value is not limited to any number nor is the y value.
Answer:
N=20
Steps:
n-17=3 (add 17 to both sides) you want N to be alone so you have to do the opposite sign which is a (+)
n=20
0.712, 0.700+0.010+0.002=0.712
Answer:
look at attached image, hope this helps! :)