Answer:
7(x+1)^2 - 3
Explanation:
To Write in The Vertex Form Simply means expressing the equation using completing of the square method
step 1: Make the coefficient of x^2 to 1
7 [x^2 + 2x + 4/7]
step 2: express the coefficient of x as half's of positive and negative
7 [x^2 + 2x + (1)^1 - (1)^1 + 4/7]
step 3: separate the negative part and the constant to solve then correct x^2 and 1^2 together
7 [ (x+1)^2 -3/7 ]
step 4 : distribute the 7
7(x + 1)^2 - 3