2-18a^2-a=-3a^2 ,5a+7-28a^2=a^2

Question

2-18a^2-a=-3a^2 ,5a+7-28a^2=a^2

Answer 1

1)

2-18a^2-a=-3a^2

-15a^2-a+2=0

15a^2+a-2=0

D=1+120=121

x1=(-1-11)/30=-2/5

x2=(-1+11)/30=1/3

2)

5a+7-28a^2=a^2

29a^2-5a-7=0

D=25+812=837

x1=(5-√837)/58=(5-3√93)/58

x2=(5+3√93)/58