## College Algebra 7th Edition

$x=-5$ or $x=-1$ or $x=-9$
$(x+5)^4-16(x+5)^2=0$ Factor $(x+5)^2$ $\Rightarrow (x+5)^2\bigg((x+5)^2-16\bigg)=0$ Expand $\Rightarrow (x+5)^2\bigg((x^2+10x+25)-16\bigg)=0$ Collect $\Rightarrow (x+5)^2\bigg(x^2+10x+9\bigg)=0$ Factor $\Rightarrow (x+5)^2\bigg((x+1)(x+9)\bigg)=0$ $\Rightarrow (x+5)^2(x+1)(x+9)=0$ Zero-Product Property $x+5=0$ or $x+1=0$ or $x+9=0$ Solve $x=-5$ or $x=-1$ or $x=-9$