1. x(2x+1)=0
It means x=0 or 2x+1=0. So
x=0
2x+1=0
2x=-1
x=-1/2
2.
➡️. 4x^2-3x-11=0
(It must take the form of ax^2+bx+c=0)
4x^2-3x=11
➡️ 4x^2-3x+9/4=11+9/4 ( you take the half of the number of 3 from 3x and square it. The half of 3 is 3/2 and when you square it becomes 9/4.)
➡️ 4x^2-3x+9/4=31/4
➡️. [4x^2-3/2]=31/4
( You put 9/4 in square root first. That means 3/2. since 3x is negative you also take negative for 3/2.)
➡️ 4x^2-3/2= positive or negative 31/4.
➡️. 4x^2=31/4+3/2
➡️. 4x^2= 37/4
➡️. x^2= 37/8
➡️. x= the square root of 37/8
