CPM Homework Help : CCA2 Problem 9-25

Rearrange the equation $y = 2x^2 + 8x + 5$ into a more useful form for graphing. State the locator point and draw the graph.

Hint:

Complete the square.

Step 1:

Factor a $2$ out of the first two terms.

$y=2(x^{2}+4x)+5$

Step 2:

Add $4$ inside the ( )s which is really adding 8 because of the $2$ multiplier. So, subtract $8$ on the same side to keep the same value.

$y=2(x^{2}+4x+4) +5 -8$

Step 3:

Simplify.

Partial Answer:

$y=2(x+2)^{2}-3$