Question 708267
The common denominator is {{{ 10 }}}
{{{ -4/5 = -8/10 }}}
{{{ 1/2 = 5/10 }}}
So, now you have
{{{ -8/10 - 7/10 + 5/10 }}}
{{{ -15/10 + 5/10 }}}
{{{ -10/10 = -1 }}}
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The answer is
{{{ - 4/5 - 7/10 + 1/2 = -1 }}}