Question 2598
4x2 + 9 = 12x
=> 4x2 - 12x + 9 = 0

Now the equation is of the form
ax2 + bx + c = 0

Multiply a and c.....and factorize the product 'ac' such that the sum of the factors is b

In our case a=4 b = -12 and c = 9

a*c = 4*9 = 36

Now we have to split 36 into factors whose sum is -12
so 36 = (-6)*(-6)
and sum of -6 and -6 is -12

therefore,
4x2 -12x + 9 =0 can be written as
4x2 -6x -6x + 9 = 0
=> 2x(2x-3)-3(2x-3)=0
=> Taking the common factore (2x-3) out
=> (2x-3)(2x-3)=0
According to the zero product factor....
2x-3 = 0
=> x = 3/2

Similarly others can be solved