Vector a is 2.80 cm long is 60 degrees above x-axis in the first quadrant. vector b is 1.90 cm long and is 60 degrees below the x-axis in the fourth quadrant. show the proper equation to get the answer of a-b and b-a. i don't know how subtract the equation i want to see the right one so i can try to get the answer by myself.

So, you know how to add, right? Subtraction is just taking the negative one, making it the other direction, and then adding the two in the proper order. So, for example, a 1.00 cm long vector 45 degrees above the x-axis, and the same below it (let the first be a and the second be b, and have both be directed away from the origin). A-B in that case would be the square root of 2, at 90 degrees off the x-axis. The first file I attached was the regular adding, and the second was the subtraction. 

British cologoinst admisitrion

D=m/v m=d*vd=densitym=massv=volumed(ether)=0.71 gr/cm³=0.71 gr/ mlv=130 mlm=d*vm=0.71 gr/ml*(130 ml)=92.3 gm=92.3 g