Answer:
[tex]4(x+1)(x+4)=0 \text{ or } 4x^2 +20x+16=0[/tex]
Step-by-step explanation:
The quadratic equation can be written in two ways:
[tex]ax^2 +bx+c=0[/tex]
or
[tex]a(x-x_1)(x-x_2)=0[/tex]
where [tex]a[/tex] is the leading coefficient and [tex]x_1, x_2[/tex] are roots of the equation.
You are given
[tex]a=4\\ \\x_1=-1\\ \\x_2=-4[/tex]
Hence, it is easier to write the quadratic equation in the second form:
[tex]4(x-(-1))(x-(-4))=0\\ \\4(x+1)(x+4)=0[/tex]
If you myltiply all terms then the equation will be written in the first form:
[tex]4\cdot x^2+4\cdot 4x+4\cdot x+4\cdot 1\cdot 4=0\\ \\4x^2 +20x+16=0[/tex]
