Is d=12 a solution to this equation? d+12=42 yes no

## Step 1: Substitute $d = 12$ into the equation<br />### Replace $d$ with $12$ in the equation $d + 12 = 42$.<br />## Step 2: Simplify the equation<br />### Calculate $12 + 12$ and check if it equals $42$.<br /><br />\[<br />12 + 12 \stackrel{?}{=} 42<br />\]<br /><br />## Step 3: Verify the result<br />### Simplify the left-hand side to see if it matches the right-hand side.<br /><br />\[<br />24 \neq 42<br />\]<br /><br />Since $24 \neq 42$, $d = 12$ is not a solution to the equation $d + 12 = 42$.