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Solve |1-4x| > 7
(x-1.5 (xlx < -1.5 UX>1.5)
(xx<-1.5 UX > 2)

1 Answer

7 votes

If
1-4x\ge0, then by definition of absolute value


|1-4x| = 1-4x > 7 \implies 4x < -6 \implies x < -\frac32

On the other hand, if
1-4x<0, then


|1-4x| = -(1-4x) = -1 + 4x > 7 \implies 4x > 8 \implies x > 2

So, the overall solution to the inequality is interval union


\left(x < -\frac32\right) \cup (x > 2)

User Munsifali
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