Question

The standard form of the equation of a parabola is v=7x^2+14x+4

Answer 1

Complete the squaer

gropu x terms
y=(7x²+14x)+4
factor out quadratic coefient
y=7(x²+2x)+4
take 1/2 of the linear coefieint and squaer it
2/2=1, (1)²=1
add positive and negiatve of it inside parnthaees
y=7(x²+2x+1-1)+4
factor perefect square trinomial
y=7((x+1)²-1)+4
distribute
y=7(x+1)²-7+4
y=7(x+1)²-3

answer is C

Answer 2

Answer should be C. If you simplify the vertex equation y=7(x+1)^2 -3, you end up with the standard equation.

y=7(x^2 + 2x + 1) -3
y= 7x^2 + 14x + 7 - 3
y= 7x^2 + 14x + 4