Question 1086038
49x^2+56x-64 = 0
49x^2+56x=64
(7x+4)^2=64+16
(7x+4)^2=80
a+b+c=7+4+80=91 ANSWER
7x+4 should equal about 9, so the root about 5/7; 7x+4 should equal about -9, so root about -1.9.
{{{graph(300,300,-5,5,-100,100,49x^2+56x-64)}}}