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14. Find the smallest number by which 2925 must be difind the square root of the perfect square so obtained.15. 1225 plants are to be planted in a garden in such a way that each row contains asmany plants as the number of rows. Find the number of rows and the number of plants in​

Answer»

1. First, we NEED to do prime factorization of 2925.

\begin{array}{r | l} 3 & 2925 \\ \cline{<klux>2</klux>-2} 3 & 975 \\ \cline{2-2} 5 & 325 \\ \cline{2-2} 5 & 65 \\ \cline{2-2}  & 13 \\ \end{array}

2925 ⇒ (3\times 3)\times (5\times 5)\times 13

∴ 13 doesn't have a PAIR. So 13 is the smallest number that can be divided by 2925 to get a perfect square.

2925\div 13=225

Now lets prime factorize 225 to get the square root.

\begin{array}{r | l} 3 & 225 \\ \cline{2-2} 3 & 75 \\ \cline{2-2} 5 & 25 \\ \cline{2-2}  & 5 \\  \end{array}

225 ⇒ (3\times 3)\times (5\times5)

Now we need to TAKE one number from each pair to find the square root.

\sqrt{225}=3\times5

\sqrt{225}=15

∴So the square root of the perfect square is ⇒  \sqrt{225}=15

2. Number of plants ⇒ 1225

Number of plants in each row ⇒ \sqrt{1225}

To find \sqrt{1225} we need to prime factorize it.

\begin{array}{r | l} 5 & 1225 \\ \cline{2-2} 5 & 245 \\ \cline{2-2} 7 & 49 \\ \cline{2-2}  & 7 \\  \end{array}

1225 ⇒ (5\times 5)\times (7\times 7)

Now we need to take one number from each pair to find the square root.

\sqrt{1225}=5\times 7

\sqrt{1225}=35

∴ 35 plants will be in each row.



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