In Text Questions Try These (Textbook No. 51, 53, 54, 56,57,60,65,66) - Chapter 3 Algebra Term 1 7th Maths Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

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On April 24, 2024, 11:35 AM

Text Questions : Chapter 3  Algebra Term 1 Class 7th std Maths Guide Samacheer Kalvi Solutions
Exercise $3.1$
Try These (Text Book Page No. 51)
Question $1 .$
Identify the variable and constants among the following terms.
$\mathrm{a}, 11-3 \mathrm{x}, \mathrm{xy},-89,-\mathrm{m},-\mathrm{n}, 5,5 \mathrm{ab},-53 \mathrm{y}, 8 \mathrm{pqr}, 18,-9 \mathrm{t},-1,-8$
Solution:
Variable : $\mathrm{a},-3 \mathrm{x}, \mathrm{xy},-\mathrm{m},-\mathrm{n}, 5 \mathrm{ab}, 3 \mathrm{y},-9 \mathrm{t}, 8 \mathrm{pqr}$
Constants : $11,-89,5,-5,18,-1,-8$

Question $2 .$
Complete the following table.

Try this (Text book Page No. 53)
Question $1 .$
Can we use the operations multiplication and division to combine terms?
Solution:
No, We can use addition and subtraction to combine terms.
If we use multiplication or division to combine then it become a single term.
$\mathrm{Eg}: \mathrm{xy}, \frac{z}{y}$ are monomials.

Try This (Text book Page No. 54)
Question $1 .$
Complete the following table by forming expressions using the terms given. One is done for you.

Try this (Text book Page No. 56 )
Question $1 .$
Identify the like terms among the following and group them.
$7 x y, 19 x, 1,5 y, x, 3 y x, 15,-13 y, 6 x, 12 x y,-5,16 y,-9 x, 15 x y, 23,45 y,-8 y, 23 x,-y, 11$
Solution:
$7 x y, 3 y x, 12 x y, 15 x y$, are like terms
$19 x, x, 6 x,-9 x, 23 x$, are like terms
$5 y,-13 y, 16 y, 45 y,-8 y,-y$, are like terms
$1,15,-5,23,11$, are like terms.

Try This (Text book Page No. 57)
Question $1 .$
Try to find the value of the following expressions if $\mathrm{p}=5$ and $\mathrm{q}=6$.
(i) $p+q$
(ii) $q-p$
(iii) $2 p+2>q$
(iv) $p q-p-q$
(v) $5 \mathrm{pq}-1$
Solution:
(i) Given $\mathrm{p}=5 ; \mathrm{q}=6$
$p+q=5+6=11$
(ii) $q-p=6-5=1$
(iii) $2 p+2>q=2(5)+3(6)=10+18=28$
(iv) $\mathrm{pq}-\mathrm{p}-\mathrm{q}=(5)(6)-5-6=30-5-6=25-6=19$

Exercise $3.2$
Try These (Text book Page No. 59)
Question $1 .$
Add the terms
(i) $3 \mathrm{p}, 14 \mathrm{p}$
(ii) $\mathrm{m}, 12 \mathrm{~m}, 21 \mathrm{~m}$
(iii) $11 \mathrm{abc}, 5 \mathrm{abc}$
(iv) $12 \mathrm{y},-\mathrm{y}$
(v) $4 x, 2 x,-7 x$.
Solution:
(i) $3 \mathrm{p}+14 \mathrm{p}=17 \mathrm{p}$
(ii) $m+12 m+21 m=(1+12+21) m$
$=34 \mathrm{~m}$
(iii) $11 a b c+5 a b c=(11+5) a b c$
$=16 \mathrm{abc}$
(iv) $12 \mathrm{y}+(-\mathrm{y})=(12+(-1)) \mathrm{y}$
$=(12-1) \mathrm{y}$
$=11 \mathrm{y}$
(v) $4 x+2 x+(-7 x)=(4+2+(-7)) x$
$=(6+(-7)) x$
$=-1 \mathrm{x}$

Ty this (Text Book Page No. 60)
Question $1 .$
$3 x ;+(y-x)=3 x+y-x$, but $3 x-(y-x) \neq 3 x-y-x$. why ?
Solution:
In the first case
LHS $=3 x+(y-x)=3 x+y-x=3 x-x+y=(3-1) x+y$
$=2 x+y$
RHS $=3 x+y-x=2 x+y$
LHS $=$ RHS $\Rightarrow 3 x+(y-x)=3 x+y-x$
But in the second case
LHS $=3 x-(y-x)=3 x-y+x$
$=(3+1) x-y=4 x-y$
RHS $=3 x-y-x=3 x-x-y$
LHS $\neq$ RHS
$\therefore 3 x-(y-x) \neq 3 x-y-x$

Exercise $3.3$
Try These (Text book Page No. 65 )
Question $1 .$
Try to construct algebraic equations for the following verbal statements.

Question 1 .
One third of a number plus 6 to 10 .
Solution:
$\frac{1}{3}+6=10$

Question $2 .$
The sum of five times of $x$ and 3 is 28
Solution:
$5(x+3)=28$

Question $3 .$
Taking away 8 from y gives 11
Solution:
$y-8=11$

Question 4 .
Perimeter of a square with side $\mathrm{a}$ is $16 \mathrm{~cm}$.
Solution:
$4 \times \mathrm{a}=16$

Question $5 .$
Venkat's mother's age is 7 years more than 3 times venkat's age. His mother's age is 43 years.
Solution:
$3 x+7=43$, where $x$ is venkat's age.
 

Try this (Text book Page No. 65)
Question $1 .$
Why should we subtract 5 and not some other number ? why don't we add 5 on both sides? Discuss.
Solution:
Given $x+5=12$
(i) Our aim is to find the value of $x$. Which means we have to eliminate the other values from LHS. Since 5 is given with $x$ it should be subtracted.
(ii) If we add 5 on both sides we cannot eliminate the numbers from LHS and we get $x+10$.

Try this (Text book Page No. 66)
Question $1 .$
If the dogs, cats and parrots represents unknown find them. Substitute each of the values so obtained in the equations and verify the answers.
Solution:
(i) $1 \operatorname{dog}+1 \operatorname{dog}+1 \operatorname{dog}=24$
$3 \mathrm{dog}=24$
$1 \operatorname{dog}=\frac{24}{3}=8$
$1 \operatorname{dog}=8$

(ii) 1 dog $+1$ cat $+1$ cat $=14$
$1 \mathrm{dog}+2 \mathrm{cat}=14$
$8+2 \mathrm{cat}=14$
$2 \mathrm{cat}=14-8$
$\begin{aligned}
&2 \text { cat }=6 \\
&\text { cat }=\frac{6}{2}=3
\end{aligned}$
ditional Questions $63^{\prime \prime}$ width $=107^{\prime \prime}$ height $=" 87^{\prime \prime} />$
(iii) 1 dog $+1$ cat $-1$ parrot $=9$
$8+3-1$ parrot $=9$
$8+3-9=1$ parrot
$11-9=1$ parrot
$2=1$ parrot
1 parrot $=2$
(iv) 1 dog $+1$ cat $+1$ parrot $=$ ?
$8+3+2=13$
Verification:
(i) $8+8+8=24$
(ii) $8+3+3=14$
(iii) $8+3-2=9$
(iv) $8+3+2=13$