4a² + 21a + 5 = 0

Question

4a² + 21a + 5 = 0

anonymous · Answer

by which method do you want to solve it @chloeLuk_siak  ?

anonymous · Answer

factorise

anonymous · Answer

well,  try making out the factors first..

wolf1728 · Answer

Wouldn't it be difficult to factor?  The numbers 4, 21 and 5 don't have any common factors.

anonymous · Answer

$$a x^{2} +bx + c = 0$$ its the standard form of the equation and to factorise it you need to make the multiplication of "a" and " c" equal to the multiplication of two terms which add equal to "b"
and in this case
4a² + 21a + 5 =  0
ac = 20
and hence the two factors which add upto 21 and give the multiplication as 20 are 20 and 1
so
4a² + 20a + a + 5 = 0
now lets take 4 common from the first 2 terms and 1 from the last two
=> 4a ( a + 5) + 1 ( a + 5 ) = 0
=> (a+5) ( 4a +1)

anonymous · Answer

and if something is not clear , feel free to ask..

anonymous · Answer

@chloeLuk_siak  ??