Question 921392
Since the triangles are similar, I can say:
BC / AC = EF / DF
These are corresponding sides in each triangle
{{{ 16 / ( 4x + 5 ) = 24 / ( 4x + 11 ) }}}
Divide both sides by {{{ 8 }}}
{{{ 2 / ( 4x + 5 ) = 3 / ( 4x + 11 ) }}}
Multiply both sides by {{{ ( 4x + 5 )*( 4x + 11 ) }}}
{{{ 2*( 4x + 11 ) = 3*( 4x + 5 ) }}}
{{{ 8x + 22 = 12x + 15 }}}
{{{ 4x = 7 }}}
{{{ x = 7/4 }}}
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{{{ 4x + 5 = 4*(7/4) + 5 }}}
{{{ 4x + 5 = 12 }}}
and
{{{ 4x + 11 = 4*(7/4) + 11 }}}
{{{ 4x + 11 = 18 }}}
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Hope this helps