Question 310639
Evaluate the variable expression when .a=-1/4, b=7/8, and c=1/8
8a + (7b -c)



Just "plug" in the info you are given, like this:


a = {{{-1/4}}}
b = {{{7/8}}}
c = {{{1/8}}}


8a + (7b - c)  (original equation)
8{{{(-1/4)}}} + ({{{7(7/8)}}} - {{{1/8}}})  (see where the fractions are substituted in for the variables?)
{{{-8/4)}}} + {{{(49/8    -    1/8)}}}  (If you multiply 8 times {{{-1/4}}} you will get {{{-8/4}}} and... If you multiply 7 times {{{7/8}}} you will get {{{49/8}}})  
{{{-8/4 + 48/8}}}  (If you subtract:  {{{49/8 - 1/8}}} you get:  {{{48/8}}})
{{{-2 + 6}}}  (Reduce the fractions:  {{{-8/4 = -2}}} and {{{48/8 = 6}}})
{{{4}}}  (if you take -2 + 6 you will get 4)


I hope this helps you. :-)