Question 942410
{{{matrix(1,9,    20,",",77/4,",",37/2,",",71/4,",","...")}}}

{{{matrix(1,7,  2nd,term,""-"",1st,term,""="",77/4-20=77/4-80/4=-3/4)}}}

{{{matrix(1,7,  3rd,term,""-"",2nd,term,""="",37/2-77/4=74/4-77/4=-3/4)}}}

{{{matrix(1,7,  4th,term,""-"",3rd,term,""="",71/4-37/2=71/4-74/4=-3/4)}}}

{{{matrix(1,7,       So,common,difference,""="",d,""="",-3/4)}}}

{{{matrix(1,9,a[n],""="",a[1]+(n-1)d,""<"","0",",",a[1]=20,",",d=-3/4 )}}}

{{{matrix(1,3,20+(n-1)expr(-3/4),""<"",0)}}}

{{{matrix(1,6,Multiply,through,by,-4,flipping,inequality)}}}

{{{matrix(1,3,-80+(n-1)(3),"">"",0)}}}

{{{matrix(1,3,-80+3(n-1),"">"",0)}}}

{{{matrix(1,3,-80+3n-3,"">"",0)}}}

{{{matrix(1,3,3n-83,"">"",0)}}}

{{{matrix(1,3,3n,"">"",83)}}}

{{{matrix(1,3,n,"">"",83/3)}}}

{{{matrix(1,3,n,"">"",27&2/3)}}}

{{{matrix(1,8,So,the,first,negative,term,is,when,n=28)}}}

{{{matrix(1,3,a[n],""="",a[1]+(n-1)d)}}}

{{{matrix(1,3,a[28],""="",20+(28-1)*(-3/4)=20+27(-3/4)=80/4-81/4=-1/4)}}}

{{{matrix(1,1,Edwin)}}}</pre>