Question 168683
Let L = the length and W = the width.
The perimeter of a rectactangle is given by:
{{{P = 2(L+W)}}}
From the problem, you have L = 2W+8 (The length is 8 in. more than twice its  width). And P = 70 in.  Substitute these for L and P in the formula.
{{{70 = 2((2W+8)+W)}}} Simplify.
{{{70 = 2(3W+8)}}}
{{{70 = 6W+16}}} Subtract 16 from both sides.
{{{54 = 6W}}} Divide both sides by 6.
{{{9 = W}}} and
{{{L = 2W+8}}}
{{{L = 2(9)+8}}}
{{{L = 18+8}}}
{{{L = 26}}}
The length is 26 in. and the width is 9 in.
Check:
{{{P = 2(L+W)}}} Substitute L = 26 and W = 9
{{{P = 2(26+9)}}}
{{{P = 2(35)}}}
{{{P = 70}}} It checks!