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Question Number 7234 by WagST last updated on 17/Aug/16
need help with step by step. thanks.    x(x+4)(x−1)=2x(x+4)
needhelpwithstepbystep.thanks.x(x+4)(x1)=2x(x+4)
Answered by Yozzia last updated on 17/Aug/16
x(x+4)(x−1)=2x(x+4)   (∗)  Adding  −2x(x+4) on both sides of (∗) gives  x(x+4)(x−1)−2x(x+4)=2x(x+4)−2x(x+4)  ∵ 2x(x+4)−2x(x+4)=0  ∴ x(x+4)(x−1)−2x(x+4)=0  By the distributive law a(b+c)=ab+bc  ⇒ x(x+4)[(x−1)−2]=0  ⇒ x(x+4)[x−3]=0  Now, in general, a product a×b×c×...×z=0  iff at least one of a,b,c,...,z is zero.  Hence for x(x+4)(x−3)=0 at least  one of x, (x+4) or (x−3) is zero.  ∴ x=0 or x=−4 or x=3.
x(x+4)(x1)=2x(x+4)()Adding2x(x+4)onbothsidesof()givesx(x+4)(x1)2x(x+4)=2x(x+4)2x(x+4)2x(x+4)2x(x+4)=0x(x+4)(x1)2x(x+4)=0Bythedistributivelawa(b+c)=ab+bcx(x+4)[(x1)2]=0x(x+4)[x3]=0Now,ingeneral,aproducta×b×c××z=0iffatleastoneofa,b,c,,ziszero.Henceforx(x+4)(x3)=0atleastoneofx,(x+4)or(x3)iszero.x=0orx=4orx=3.

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