Respuesta :

Hi there,

No. 1:

[tex]64<68<81\Rightarrow \sqrt{64}<\sqrt{68}<\sqrt{81},\;or\;\sqrt{8^2}<\sqrt{68}<\sqrt{9^2}\Rightarrow\\\\\Rightarrow therefore\;8<\sqrt{68}<9.[/tex]

The answer is 8.2 ft, for sure.

Having this technique in mind, can you resolve the rest of 4 math questions, by yourself ? It is quite simple, isn't it ?

Green eyes.


to estimate
find the perfect squares above and below the target number
guess
example
sqrt of 99
9^2=81
10^2=100
99 is between 81 and 100, closer to 100 so therefor pick 10.9 or something


1.
if we estimate
8^2=64
that is close to 68
8.2^2 is probably closer sinnce is is bigger than 0.2

therefor the answer is A




2. estimate
12^2=144
13^2=169
148 is betwen 12 and 13
pick B

3. 114
square aera=side^2
10^2=100
11^2=121
see if it is more than 10.5 or less
which is closer 114
100 or 121
121 is closer
therefor we guess that it is greater and therefor we should guess 11 yards


4. area=side^2
196=side^2
luckily we remembered tat 14^2=196
1 side=14 ft
perimiter=4side
P=4*14=56 ft


5.
area=side^2
480=side^2
sqrt both sides
√480=√16√30=4√30
aprox sqrt 30
between 5 and 6, lookks like in middle
aprox 5.5
4*5.5
perimiter is times 4
4*4*5.5=16*5.5=80+8=88 feet
answer is D