SChand Composite Mathematics Class 7 Chapter 6 Algebraic Expression Exercise 6C

 EXERCISE  6C

Question 1

Subtract the lower term from the upper term: 

(i) 

$\begin{array}{r}5x \\-3x \\\hline 2 x \\\hline\end{array}$

(ii)

$\begin{aligned}&-3 a \\&7 a \\&\hline 4 a \\&\hline\end{aligned}$

(iii)

$\begin{array}{r}-6 b^{2} \\+4 b^{2} \\\hline-10 b^{2} \\\hline\end{array}$

(iv) 

$\begin{array}{r}3 \mathrm{~m} \\-2 \mathrm{~m} \\\hline 5 \mathrm{~m} \\\hline\end{array}$

(v)

$\begin{array}{r}5 c d \\-\quad 0 \\\hline 5 c d \\\hline\end{array}$

(vi)

$\begin{aligned}& 0 \\-& 3 a \\\hline 3 a\end{aligned}$

(vii) 

$\begin{array}{r}7 a b^{2} \\-7 a b^{2} \\\hline 0 \\\hline\end{array}$

(viii) (IMAGE TO BE ADDED)

(IX) (IMAGE TO BE ADDED)

(X)

$\begin{aligned}& 5 a b c \\-& 5 a b c \\\hline & 10 a b c \\\hline\end{aligned}$

(xi)

$\begin{array}{r}-3 x^{3} \\+3 x^{3} \\\hline 0\end{array}$

(xii)  (IMAGE TO BE ADDED)

Question 2

(i) 

 $\begin{array}{r}5 a+6 \\-4 a \pm 3 \\\hline a+3\end{array}$

(ii)

$\begin{aligned}&7 x+2 \\&-4 x+5 \\&\hline 3 x-3 \\&\hline\end{aligned}$

(iii)

$\begin{array}{r}5 p+6 \\-p \mp 3 \\\hline 4 p+9\end{array}$

(iv)

$\begin{array}{r}7 x^{2} y-4 \\-4 x^{2} y-7 \\\hline 3x^{2} y+3\end{array}$

(v) (IMAGE TO BE ADDED)

(vi)

$\begin{gathered}5 c d-d^{2} \\-c d \pm 3 d^{2} \\\hline 4 c d-4 d^{2}\end{gathered}$

(vii)

$\begin{aligned}& 6 m^{3}-2 n^{2} \\+& 3 m^{3}+5 n^{2} \\\hline & 9 m^{3}-7 n^{2}\end{aligned}$

(viii)

$\begin{aligned}&2 m-n\\&\frac{-m-n}{m}\end{aligned}$

(ix)

$\begin{array}{r}x-3 \\x-3 \\\hline 0+\end{array}$

(x) (IMAGE TO BE ADDED)

Question 3

(i)

$\begin{array}{r}5 p+4 q+7 c \\-3 p \pm q \pm 3 c \\\hline 2 p+3 q+4 c \\\hline\end{array}$

(ii)

$\begin{aligned}&3 x^{2}-4 x+8 \\&-4 x^{2}+2 x-11 \\&\hline-2 x^{2}-6 x+19 \\&\hline\end{aligned}$

(iii)

$\begin{aligned}&7 m^{2}+m n-4 n^{2} \\&-5 m^{2}-3 m n+n^{2} \\&\hline 2 m^{2}+4 m n-5 n^{2}\end{aligned}$

(iv)  (IMAGE TO BE ADDED)

(v)

$\begin{aligned}&0\\&\frac{-p^{3}+3 p^{2}-6 \pm p}{p^{3}-3 p^{2}+6-p}\end{aligned}$

Question 4

How much is 0 greater than  $-a^{2}-a b+7 b^{2}$

Sol: 

$\begin{gathered}0 \\-\frac{a^{2}-a b+7 b^{2}}{a^{2}+a b-7 b^{2}}\end{gathered}$

Question 5

$\begin{array}{r}4 x^{2}-2 x-6 \\-x^{2}+4 x \pm 5 \\\hline 3 x^{2}+2 x-11\end{array}$

Question 6

 (IMAGE TO BE ADDED)

Question 7

$\begin{array}{r}2 b^{2}+b c-2 c^{2} \\9 b^{2}+0-3 c^{2} \\\hline 11 b^{2}+b c-5 c^{2} \\\hline\end{array}$

$\begin{aligned}&2 b^{2}-2 b c-c^{2} \\&-b^{2}+2 b c+c^{2} \\&\hline b^{2}+0+0\end{aligned}$

$\begin{aligned}&b^{2}\\&\frac{\pm 11 b^{2}+b c-5 c^{2}}{-10 b^{2}-b c+5 c^{2}}\end{aligned}$