Answer:
17) just take the root of 100. the text says its square(d).
10m
And checking it gives 10m * 10m = 100m²
18) you need to learn some square numbers to ace this topic. it isn't that complicated, just multiply natural numbers with themselves
like
1² = 1
2² = 4
3² = 9
4² = 16
5² = 25
6² = 36
7² = 49
8² = 64
Now we can see that a) sqrt(55) lies between 7 and 8, and that its value is somewhere in between
7 < a < 8
(ignoring the negative solution to the root oc)
try b, c and d yourself. if you struggle, leave a comment.
<u>I got a problem finding exercises 19 to 21, seriously....</u>
<u>2</u><u>2</u><u>)</u><u> </u><u>well</u><u>.</u><u>.</u><u>.</u>
<u>a</u><u> </u><u>*</u><u> </u><u>b</u><u> </u><u>=</u><u> </u><u>18ft</u><u>²</u>
<u>6ft</u><u> </u><u>*</u><u> </u><u>3ft</u><u> </u><u>seems</u><u> </u><u>just</u><u> </u><u>right</u><u>.</u><u> </u><u>pure</u><u> </u><u>guesswork</u><u> </u><u>here</u><u>,</u><u> </u><u>seems</u><u> </u><u>to</u><u> </u><u>be</u><u> </u><u>to</u><u> </u><u>easy</u><u> </u><u>with</u><u> </u><u>these</u><u> </u><u>numbers</u><u>.</u>
<u>but</u><u> </u><u>we</u><u> </u><u>can</u><u> </u><u>also</u><u> </u><u>write</u><u> </u><u>it</u><u> </u><u>as</u><u> </u><u>a</u><u> </u><u>system</u><u> </u><u>of</u><u> </u><u>two</u><u> </u><u>functions</u>
<u>a * b = 18ft²</u>
<u>a</u><u> </u><u>=</u><u> </u><u>2</u><u>b</u>
<u>and</u><u> </u><u>then</u><u> </u><u>solve</u><u> </u><u>it</u><u> </u><u>by</u><u> </u><u>s</u><u>u</u><u>b</u><u>s</u><u>t</u><u>i</u><u>t</u><u>u</u><u>t</u><u>i</u><u>n</u><u>g</u><u> </u><u>a</u><u> </u><u>in</u><u> </u><u>line</u><u> </u><u>one</u><u> </u><u>with</u><u> </u><u>2</u><u>b</u><u>,</u><u> </u><u>since</u><u> </u><u>a</u><u> </u><u>is</u><u> </u><u>2</u><u>b</u><u> </u><u>this</u><u> </u><u>is</u><u> </u><u>allowed</u><u>. </u>
<u>2</u><u>b</u><u> </u><u>*</u><u> </u><u>b</u><u> </u><u>=</u><u> </u><u>1</u><u>8</u>
<u>2</u><u> </u><u>b</u><u>²</u><u> </u><u>=</u><u> </u><u>1</u><u>8</u>
<u>b</u><u>²</u><u> </u><u>=</u><u> </u><u>9</u>
<u>b</u><u> </u><u>=</u><u> </u><u>3</u>
<u>(</u><u>we</u><u> </u><u>ignore</u><u> </u><u>-3</u><u> </u><u>as</u><u> </u><u>a</u><u> </u><u>solution</u><u> </u><u>bc</u><u> </u><u>negative</u><u> </u><u>length</u><u> </u><u>makes</u><u> </u><u>no</u><u> </u><u>sense</u><u>)</u>
<u>plugging</u><u> </u><u>that</u><u> </u><u>b</u><u> </u><u>into</u><u> </u><u>line</u><u> </u><u>two</u><u> </u><u>of</u><u> </u><u>the</u><u> </u><u>system</u><u> </u><u>gives</u>
<u>a</u><u> </u><u>=</u><u> </u><u>2</u><u> </u><u>*</u><u> </u><u>3</u>
<u>a</u><u> </u><u>=</u><u> </u><u>6</u>
<u>2</u><u>7</u><u>)</u><u> </u><u>rationale</u><u> </u><u>can</u><u> </u><u>we</u><u> </u><u>written</u><u> </u><u>as</u><u> </u><u>a</u><u> </u><u>ratio</u><u> </u><u>(</u><u>a</u><u> </u><u>fration</u><u>)</u>
<u>it</u><u> </u><u>almost</u><u> </u><u>sounds</u><u> </u><u>too</u><u> </u><u>simply</u>
<u>rationals</u><u> </u><u>are</u><u> </u><u>either</u><u> </u><u>the</u><u> </u><u>root</u><u> </u><u>of</u><u> </u><u>square</u><u> </u><u>numbers</u><u>, </u><u>bc</u><u> </u><u>they</u><u> </u><u>can</u><u> </u><u>be</u><u> </u><u>solved</u><u> </u><u>cleanly</u><u>, </u><u>or</u><u> </u><u>they</u><u> </u><u>got</u><u> </u><u>a</u><u> </u><u>repeating</u><u> </u><u>pattern</u><u> </u><u>after</u><u> </u><u>the</u><u> </u><u>point</u><u>.</u>
<u>b</u><u> </u><u>and</u><u> </u><u>c</u><u> </u><u>apply</u><u> </u><u>to</u><u> </u><u>these</u><u> </u><u>rules</u><u>,</u><u> </u><u>a</u><u> </u><u>and</u><u> </u><u>d</u><u> </u><u>not</u>
<u>30) lol, I just figured out where the missing exercises are hidden</u> XD
31) just add up the three rectangles (easy part) with the two triangles top and bottom each triangle is just 12m * 16m / 2 (bc it's a triangle, not a rectangle). since you got two triangles you just multiply by two (it's like ignoring the decision. also, the two triangles together would indeed make just a n9ce rectangle).
if you really need the values, leave a comment, but that will not help you in any test.
you can also post your solutions and I'll check them.
32) area of the circle times two
plus area of a rectangle wrapped around the cylinder.
circle are is pi*r² -> pi * (28 in)²
(remember to double for two circles)
rectangle is the circumference of the circle (pi * 28in) times the height of the cylinder
like in 31), feel free two post your results or ask for values if you really struggle to grasp the pattern here.
hope you have a great day and that you understand some more of the topic. you can ace it :)