Question 1151854
{{{ A = (1/2)*b*h }}}
{{{ 48 = (1/2)*b*h }}}
(1) {{{ b*h = 96 }}}
and
(2) {{{ h = b - 4 }}}
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Plug (2) into (1)
(1) {{{ b*( b - 4 ) = 96 }}}
(1) {{{ b^2 - 4b - 96 = 0 }}}
(1) {{{ ( b - 12 )*( b + 8 ) = 0 }}}
(1) {{{ b = 12 }}}
The base is 12 m
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check:
{{{ A = (1/2)*b*h }}}
{{{ A = (1/2)*12*h }}}
{{{ 48 = 6h }}}
{{{ h = 8 }}}
and
{{{ h = b - 4 }}}
{{{ 8 = 12 - 4 }}}
{{{ 8 = 8 }}}
OK