Question

Solve each equation using trial and error method

$\frac{a}{3}+4=7$

Answer 1

Solving equation using trial and error method

As$RHS=7$ which is a whole number

So, value of $a$must be completely divisible by $3$

$a$	$LHS$	$RHS$
$3$	$\frac{a}{3}+4=\frac{3}{3}+4=1+4=5$	$7$	$LHS\ne RHS$
$6$	$\frac{a}{3}+4=\frac{6}{3}+4=2+4=6$	$7$	$LHS\ne RHS$
$9$	$\frac{a}{3}+4=\frac{9}{3}+4=7$	$7$	$LHS=RHS$
$12$	$\frac{a}{3}+4=\frac{12}{3}+4=8$	$7$	$LHS\ne RHS$

From the table, we find that $LHS=RHS$ when $a=9$

Hence, the solution of given equation is $a=9$