How do you determine whether (-1, -1) and (1, -1) is a solution to $y < 2x + 1$ ?

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Answer 1 · 2015-07-23T00:07:06

$(1,-1)$ is a solution to the inequality $y<2x+1$ .

$y<2x+1$

Substitute $(-1,-1)$ and $(1,-1)$ for $x$ and $y$ into the inequality.

Point $(-1,-1)$
$x=-1$
$y=-1$

$-1<2(-1)+1$ =

$-1<-2-1$ =

$-1<-3$

This is a false statement. $(-1,-1)$ is not a solution.

Point $(1,-1)$
$x=1$
$y=-1$

$-1<2(1)+1$ =

$-1<2+1$ =

$-1<3$

This is a true statement. $(1,-1)$ is a solution.
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