Question 211149
if (a,4) is a point on the graph of y=4x-3, then 
x = a
y = 4
satisfy the equation y = 4x - 3

Substituting x = a, y = 4 into the equation, we have
4 = 4a -3
Solving the equation for a, we have
7 = 4a
a = 7/4