Question 200455
Add:
{{{((a+7)/(a-4))+((9-5a)/(a-4))}}} Since both fractions are over a common denominator, (a-4), you can add the numerators and put them over the common denominator:
{{{(a+7+9-5a)/(a-4)}}} Now simplify the numerator.
{{{(16-4a)/(a-4)}}} Factor a 4 from the numerator.
{{{4(4-a)/(a-4)}}} Rewrite the numerator: {{{4*(4-a) = -4*(a-4)}}}and substitute.
{{{(-4*cross((a-4)))/(cross((a-4)))}}} which leaves you with:
{{{highlight(-4)}}} as your answer.