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Verified Answer :

4x^2 + 40 x
=  4 (x^2 + 10x) 
= 4 (x+ 5)^2 - 25)
 = 4(x + 5)^2 - 100

Answer:

\(g(x) =4(x+5)^2-100\)

Step-by-step explanation:

\(g(x) = 40x + 4x^2\)

To get vertex form of equation y =a(x-h)^2+k

we use completing the square method

In completing the square method we take coefficient of x ,divide by 2 and then we square it

To apply completing the square method, we make x^2 alone

\(g(x) =4x^2+40x\)

\(g(x) =4(x^2+10x)\)

Coefficient of x is 10 , 10 divide by 2= 5

5^2= 25

Add and subtract 25

\(g(x) =4(x^2+10x+25-25)\)

\(g(x) =4(x^2+10x+25)-100\)

Now factor x^2 +10x+25, it becomes \((x+5)(x+5)\)

\(g(x) =4(x+5)(x+5)-100\)

\(g(x) =4(x+5)^2-100\) is our vertex form