X Coordinate: (-3a + 3a)/2
0/2 = 0
Y Coordinate: (b + b)/2
2b/2 = b
Midpoint: (calculated x, calculated y)
In this case, the midpoint should be (0, b)
Well if you're asking for it to be in a fraction, then it's already in its simpliest form. but for a decimal, it would be 0.8833
The best thing to do is to find what 1% is, and you can do this by dividing 150 by 100.
150/100= 1.5
As you're looking for 6.5%, you've got to multiply 1.5 by 6.5
1.5*6.5= 9.75
You've then got to add 9.75 and 150 together
150+9.75= $159.75
Therefore, after the sales tax, the cost of the necklace is $159.75
Hope this helps :)