Please help Maggie's brother is 3 years younger than twice her age. The sum of their ages is 30. How old is Maggie

I’m not sure if this is correct but this is the way i would solve it.

first, make an equation with the given information

2x-3=30

Then, add three to both sides

2x=33

Finally, divide both sides by 2

x= 16.5

x represents the age of maggie so all you have to do is plug the solution into the equation to check your answer.

2(16.5)-3= 30

If gravity is one third on mars then weight also one third on mars

The discount is 8.70 . you dont tell us the percent of tax added so there is no way to find out, unless i'm not seeing anything. without tax its 37.70