Question

Solve : $4x=28$ by the trial-and-error method.

Answer 1

From above $4x=28$

At $x=1$, LHS$=4\times 1=4\ne 28$

At $x=2$, LHS$=4\times 2=8\ne 28$

At $x=3$, LHS$=4\times 3=12\ne 28$

At $x=4$, LHS$=4\times 4=16\ne 28$

At $x=5$, LHS$=4\times 5=20\ne 28$

At $x=6$, LHS$=4\times 6=24\ne 28$

At $x=7$, LHS$=4\times 7=28=28$

$\therefore x=7$ is the root of the equation