H varies directly as L. H=18 when L=60, determine H when L=20

Hurry and answer this! circle x with a radius of 6 units and circle y with a radius of 2 units are shown which steps would prove the circles similar? translate the circles so they share a common center point, and dilate circle y by a scale factor of 4. translate the circles so the center of one circle rests on the edge of the other circle, and dilate circle y by a scale factor of 4. translate the circles so they share a common center point, and dilate circle y by a scale factor of 3. translate the circles so the center of one circle rests on the edge of the other circle, and dilate circle y by a scale factor of 3

Bring the fraction a/a-4 to a denominator of 16-a^2

What is the slope of any line parallel to the line 8x+9y=3 in the standard (x,y) coordinate plane?