Question

(X-3)(4x+1)=0 that is the solution of X

Answer 1

The equation is already factored so, set each factored form to 0.
(x-3)=0 (4x+1)=0

Then, solve each equation.
x-3=0 4x+1=0
+3 +3 -1 -1
______ ______
x=3 4x=-1
--- ---
4 4
______
x=-1/4

So x could be either 3 or -1/4.