What they want you to do is make a rough guess (in your head) about what the total cost might be. You can break it down into smaller numbers to make this easier!
Since you don’t have to be accurate (because it is an ‘estimate’, meaning it’s not exact), let’s round the price to $180. Now, let’s separate $180 into two different parts — $100 and $80. Since there are three people, you can multiply both of those parts by 3; 100x3=300, and 80x3=240. Now, add those two numbers together. 300+240=540. $540 can be your estimate for the total price!
Now, since they want you to find the exact answer afterwards, we’re going to go back in and find the exact answer. I’m not sure if you’re too familiar with multiplication yet, so let’s do it using addition! 179+179=358. Then, add another 179... 358+179=$537.
So, the exact cost would be $537! Does that make sense? Your estimate was *close*, but not exact because we rounded 179 up to 180 to make it a little easier. Estimates can be really useful if you have to do math on the fly, and once you go back to get the real exact answer, you’ll know you’re right if they are quite close!
{(2, 3), (1, 5), (2, 7)} - NOT because 2->3 and 2->7 {(11, 9), (11, 5), (9, 3)} - NOT because 11->9 and 11->5 {(3, 8), (0, 8), (3, -2)}
- NOT because 3->8 and 3->-2
