Adam is going to make concrete. He is going to use 180 kg of cement. 375 kg of sand. 1090 kg of stone. Cement, sand and stone are sold in bags.

1 bag cement 25 kg
1 bag sand 22.5 kg
1 bag stone 50 kg

Adam already has
8 bags of cement
19 bags of sand
20 bags of stone

Work out what bags he needs to buy to make the concrete.

Working must be shown please.

2 bags of stone

Step-by-step explanation:

Lets do one at a time.  Cement first.

he needs 180 kg of cement.

1 bag is 25 kg, so in total he needs 8 because 7 would get him 175, so he would need just a little bit more.  And I assume you can't but part of a bag he needs to but one full more bag.  If he already has 8 then he doesn't need any more.

Needs 375 kg of sand

Each bag has 22.5 kg inside

he needs 17 bags total of sand because 16 would only give 360

Since he already has 19 bags he has 427.5 kg of sand so he doesn't need any more.

Needs 1090 kg of stone

Each bag has 50 kg of stone

He needs 22 bags since 21 would just give him 1050 kg

He has 20 so he needs two more bags

So in total he needs two bags of stone.  Let me know if there was anything you didn't understand.  

to plot points   for x just start at the origin (middle) and go to the left however many times it say(if the number is a positive) if the number is a negative then go right however many times it says if it is 0 go nowhere

now keep you pencil there and go up however many times it says on y(if it is positive) if it is negative then go down however many times it says. if it says 0 go nowhere.

you have just plotted a point! now when you finish plotting all of them connect them with a ruler

plot each point as (-3, 7), (0,4), (3,1), (8,-4)   in the parenthesis on the left of the comma is x and the right is y.