Question 997770

{{{19 = 10 - 3a}}}

{{{19+3a = 10 - 3a+3a}}}

{{{19+3a = 10 }}}

{{{19-19+3a = 10-19 }}}

{{{3a = -9 }}}

{{{a = -9/3 }}}

{{{a = -3 }}}