Question 988988
{{{ abs( 3x + 7 ) < 6 }}}
I know the left side cannot be negative, 
since it's an absolute value, so both
these must be true:
{{{ abs( 3x + 7 ) >= 0 }}}
{{{ abs( 3x + 7 ) < 6 }}}
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Suppose {{{ abs( 3x + 7 ) = 0 }}}, then
{{{ x = -7/3 }}}
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Suppose {{{ abs( 3x + 7 ) <6 }}}, 
(1) {{{ 3x + 7 < -6 }}}
and
(2) {{{ 3x + 7 < 6 }}}
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(1) {{{ 3x < -6 - 7 }}}
(1) {{{ 3x < -13 }}}
(1) {{{ x < -13/3 }}}
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(2) {{{ 3x < 6 -7 }}}
(2) {{{ 3x < -1 }}}
(2) {{{ x < -1/3 }}}
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I have 3 equations now:
{{{ x = -7/3 }}}
{{{ x < -13/3 }}}
{{{ x < -1/3 }}}
all of which must be true
{{{ x < -1/3 }}} includes all three, so
that is my answer