4x+5=x(x+8) how do I solve this?

Mathematics

1 answer:

GenaCL600 [577]2 years ago

3 0

Answer:

$x=1,-5$

Step-by-step explanation:

$We\ are\ given\ that,\\4x+5=x(x+8)\\Hence\ by\ expanding\ the\ terms,\\4x+5=x^2+8x\\Hence\ by\ moving\ 4x\ and\ 5 to\ the\ RHS\ ,\\0=x^2+8x-4x-5\\Hence\ by\ simplifying\ the\ RHS,\\0=x^2+4x-5\\Now,\\We\ take\ a\ closer\ look\ at\ the\ RHS,\\x^2+4x-5\ can\ also\ be\ written\ as:\\=x^2+5x-x-5\\Now, By\ factorizing,\\x(x+5)-1(x+5)\\=(x-1)(x+5)\\Hence,\\(x-1)(x+5)=0\\Now,\\To\ nullify\ the\ LHS\ to\ 0,\ either\ the\ term\ (x-1)\ or/and\ (x+5)\ should\ equate\ to\ 0.\\Hence,\\x-1=0\\$ $x=1\ is\ our\ first\ solution\\(x+5)=0\\x=-5\ is\ our\ second\ solution\\Hence,\\x=1,-5$

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Further explanation:

Let's go through the answer choices one by one

A. This is false because 0 does not come before -5, but instead -5 is listed first. The order -5,-4,-3,-2,-1,0 is correct meaning that $-5 \le x \le 0$ is the correct order as well.
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