Question

plzz.... help me to do this prblm​

Answer 1

Step-by-step explanation:

i) 2x^2+x-4=0

=> 2x^2+(4-2)x-4=0

=> 2x^2+4x-2x-4=0

=>2x(x+2)-2(x+2)=0

=>(x+2)(2x-2)=0

either, x+2=0, x= -2

or, 2x-2=0 , 2x=2, x=2/2, x=1

iii)5x^2-7x-6=0

=>5x^2-(10-3)x-6=0

=>5x^2-10x+3x-6=0

=>5x(x-2)+3(x-2)=0

=>(x-2)(5x+3)=0

either, x-2=0, x=2

or, 5x+3=0, 5x= -3, x= -3/5

iv) x^2+5= -6x

=>x^2+6x+5=0

=>x^2+(5+1)x+5=0

=>x^2+5x+x+5=0

=>x(x+5)+1(x+5)=0

=>(x+5)(x+1)=0

either, x+5=0, x= -5

or, x+1=0, x= -1