<p>Could someone help me?</p>
<p>pg 673 #15
pg 681 #10
pg 683 #13</p>
<p>Thanks!!!</p>
<p>Okay, for the first one, it says inclusive. So 0 and 100 will be included, one of which is a square of 10. So that's counted.
Check like if a square of 1 is included and do the same till it's 9 and 10. So there are all 10 numbers that cannot satisfy the rule mentioned in the problem.
Then just subtract them from 100, which will be 90 (E).</p>
<p>And for the second one, let's first find the amount of masking tapes that is used to stick a poster. It will be 4 pieces x 6 inches = 24 inches = 2 foot. 2 foot will be subtracted from 300 for each poster put up. So the function will be 300 - 2n.</p>
<p>Finally, for the last one, I see the answer myself easily but somehow I cannot explain it well, due to my poor English. Well, but I'll try to.
(Dunno if I'm using the right term). x and y will be outer angles that can be found by subtracting the inner angle from 180 degrees, since the angle along the line is 180.
a + b + z = 180 (z = 30)
x = 180 - a
y = 180 - b
(a and b are inner angles)
x + y = 360 - (a+b) then (a+b) is 150 from the first equation.
so x + y = 210.</p>