Question 14734
there is a formula for distance of a point (h,k) from a line given by the equation
  a*x+b*y+c=0...the formula is 
 distance = {{{(a*h+b*k+c)/(sqrt(a^2+b^2))}}}
  That is ,just substiute the given coordinates of the point (h,k)for x and y in the given equation of the line and devide it by {{{(sqrt(a^2+b^2))}}}
for the given problem we have line as 2x+y-2=0 and point as (-3,4).So a=2;b=1;c=-2;h=-3;k=4. 
distance = {{{(2*(-3)+1*4-2)/(sqrt(2^2+1^2))}}}=-4/{{{(sqrt(5))}}}