All it is asking is to plug the given x values into the equation (which are 0, 2, 4) and see what you get for y.
4y - 2x =16
4y - 2 (0) = 16
4y = 16
y = 4
4y - 2 (2) = 16
4y - 4 = 16
4y = 20
y = 5
4y - 2 (4) = 16
4y - 8 = 16
4y = 24
y = 6
so D
Train A weighs 181 tons and train B weighs 70 tons.
For the second question, your first option is correct, you would rewrite 8 in power-base form 8=2^3 as the first step to solving the equation, power base form is exponential form.
9% of $2500 = 225
7 × 225 + 2500 = $4075
