vertex form is y=a(x-h)^2+k expand and combine like terms and complete the square
expand y=x^2+6x+9+x^2+8x+16 add y=2x^2+14x+25 completet the square first move 25 off to side y=(2x^2+14x)+25 work inside we need 1 in front of x^2 undistribute 2 y=2(x^2+7x)+25 take 1/2 of 7 and squaer it and add the positive and negative inside y=2(x^2+7x+12.25-12.25)+25 factor perfec square inside y=2((x+3.5)^2-12.25)+25 distribute the -12.25 y=2(x+3.5)^2-24.5+25 add y=2(x+3.5)^2+0.5