The first coordinate of the ordered pair is the x-value, while the second coordinate corresponds to the y-value.
Part a)

Substitute x=a and y=-4 to find an equation for a:

Solve for a:

Therefore, the value of a that makes the ordered pair (a,-4) a solution to the equation 4x-3y=10, is -1/2.
Part b)

Substitute x=3 and y=a+1:

Solve for a:

Therefore, the value of a that makes the ordered pair (3,a+1) a solution to the equation y=-5x+2, is -14.