Question

$\frac{1}{2}x + 7 = 21$

Explanation:

Step1: Subtract 7 from both sides

$\frac{1}{2}x + 7 - 7 = 2.1 - 7$
$\frac{1}{2}x = -4.9$

Step2: Multiply both sides by 2

$2\times\frac{1}{2}x = -4.9\times2$
$x = -9.8$

Answer:

$x = -9.8$