- The graph of the quadratic function is a parabola. If the vertex of a parabola is at (h,k), then the equation of the parabola has the form y=a(x−h)2+k. Since it is given that (h,k)=(3,25),y=a(x−3)2+25. From the graph, you know that the y-intercept is (0,16). Plug these coordinates into the equation to find the value of the constant a :1616−9a​=a(0−3)2+25=9a+25=9a=−1​Hence, the equation of the parabola is y=−(x−3)2+25.- Find an equation of the line in y=mx+b slope-intercept form where m is the slope of the line and b is its y intercept. The y-intercept of the line is −5 so b=−5. Using the points (4,3) and (0,−5), find the slope, m, of the line:m=ΔxΔy​​= change in x-coordinates  change in y-coordinates ​=0−4−5−3​=−4−8​=2​Hence, an equation of the line is y=2x−5.- To find the coordinates of the point of intersection of the two graphs, solve the linear-quadratic system of equations:y=−(x−3)2+25y=2x−5​ Substitute 2x−5 for y in the quadratic equation: −(x−3)2+25−(x2−6x+9)+25−x2+6x+16−x2+4x+21x2−4x−21(x−7)(x−3)x=7 or x​=2x−5=2x−5=2x−5=0=0=0=−3​Since (j,k) is in the first quadrant, j=7. Find the corresponding value of y by substituting 7 for x in the linear equation, which gives y=2(7)−5=9. Hence, k=9 so jk=7×9=63.Grid-in 63