Question

Please help me! Find AC

Answer 1

We are asked to find the length of $AC$, which measures $7x$. Using the segment addition postulate, we can add the two given expressions for $AB$ and $BC$ and make it equal to the expression for $AC$. 
$AB + BC=AC$
$5x+1+15=7x$
$5x+16=7x$
$16=2x$
$x=8$
We've found the value of $x$, but we aren't done yet. We need to plug in the value we got for $x$ into the expression for $AC$, which is $7x$. Therefore, $AC \Rightarrow7x\Rightarrow7(8)\Rightarrow\boxed{56}$. Hope this helped and have a great day!