Question

solve by formula method

Answer 1

Answer:

the formula is ax^2+bx+c.

Step-by-step explanation: So the sums can be converted in this formula and be solved by middle term spilitting

eg-

in 2)-4x^2+9x+1 that is conversion then solving.

Answer 2

Answer:

1) 2x²+x-1/5 = 0

multiply the given equation by 5

2x²×5 + x-1/5×5 =0

10x²+x-1 = 0

comparing with ax²+bx+c=0

a = 10 , b = 1 , c= -1

b²-4ac = 1²-4×10×-1

= 1 +40

=41

x = -b+-√b²-4ac /2a

= -1√41/2×10

= -1 +-√41/20

2) 9x+1=4x²

4x²-9x-1=0

comparing with ax²+bc+c=0

a=4 , b=-9 ,c= -1

b²-4ac = -9²-4×4×-1

= 81+16

= 91

x= -b+-√b²-4ac/2a

= -(-9) +-√91/2×4

= 9+-√91/8

3) 2x²+5x-2=0

comparing with ax²+bx+c=0

a=2 ,b=5 , c = -2

b²-4ac= 5²-4×2×-2

= 25+16

= 41

x= -b+-√b²-4ac/2a

= -5+-√41/2×2

= -5+-√41/4