Question 657397
The rule is:
( a + b ) x ( c + d ) = ac + bc + ad + bd 
You got the ac and the bd, but you
left out the bc and ad
{{{  (7x+1/2)*(-10x-22) = -70x^2 -5x -154x - 11 }}}
{{{ -70x^2 - 159x - 11 }}}
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You can check by plugging in some value for x
I'll say {{{ x = -1/2 }}}
{{{  (7x+1/2)*(-10x-22) = (-7/2 + 1/2)*(5 - 22) }}}
{{{ (-3)*(-17) = 51 }}}
and, also
{{{ -70x^2 - 159x - 11 = -70*(1/4) - 159*(-1/2) - 11 }}}
{{{ -17 - 1/2 + 79 + 1/2 - 11 }}}
{{{ -17 + 79 - 11 = 79 - 28 }}}
{{{ 79 - 28 = 51 }}}
OK