Help please :) Choose the correct graph of the given system of equations.

y − 2x = −1
x + 3y = 4

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

If set d is not the empty set but is a subset of set e, then which of the following is true? d ∩ e = d d ∩ e = e d ∩ e = ∅