Question 712446
{{{ sqrt (b) - 6= -2* sqrt(b) }}}
Add {{{ 2*sqrt(b) }}} to each side
then add {{{ 6 }}} to both sides
{{{ sqrt(b) + 2*sqrt(b) = 6 }}}
{{{ 3*sqrt(b) = 6 }}}
{{{ sqrt(b) = 2 }}}
Square both sides
{{{ b = 4 }}}
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check:
{{{ sqrt (b) - 6= -2* sqrt(b) }}}
{{{ sqrt (4) - 6= -2* sqrt(4) }}}
{{{ 2 - 6 = -2*2 }}}
{{{ -4 = -4 }}}
OK