1,710/3 = 570 <== this is just simple division...nothing a calculator can't do.
W - 2.76 = 6.7
isolate the W by adding 2.76 to both sides of the equal sign
W - 2.76 (+2.76) = 6.7 (+2.76)
W = 6.7 + 2.76
W = 9.46
9.46 is your answer
hope this helps
Complement adds to 90
complement of A is 90-A
supplement is adds to 180
supplemetn of A is 180-A
2(90-A) is -40+180-A
2(90-A)=-40+180-A
2(90-A)=140-A
distribute
180-2A=140-A
add 2A to both sides
180=140+A
minus 140 both sides
40=A
A=40 degres