D. 21cm because you divide all sides by 2 then get your slope form and multiply by seven
Try adding 11, 11 times. It is a long process, but it should give you what you are looking for. First. to break it down add 10 eleven time, then after you get 110 add the remaining 11.
8p +5 = $29
The above is the equation
If you want to know how many pizza were ordered then you subtract 5 from each side of the equal sign then you would have 8p=24 then divide by 8 on both sides of equal sign . p= 3 ; so 3 pizzas were order plus a charge of $5 for delivery.