For a = - 5,
LHS = a² + 3a + 2
=(-5)²+3x(-5)+2=25-15+2=12
and RHS =132
\(\because LHS\neq RHS\)
So, it is not true for a = - 5
For a =0,
LHS = a² + 3a + 2
= (0)2 + 3 x 0 + 2 = 0 + 0 + 2 = 2
and RHS =132
\(\because LHS\neq RHS\)
So, it is not true for a = 0.

(a)(110)² = (100 + 10)² = (100)² + (10)² + 2 x 100 x 10
= 10000 + 100 + 2000 = 12100
(b)(89)² = (100-11)²
= (100)² + (11)² - 2 x 100 x 11 = 10000 + 121- 2200 = 7921
(c) (110)² - (89)² = (110 + 89)(110 - 89) = (199) x 21 = 4179

First expression = 3l(l - 4m + 5n)
= (3l) x (l) - (3l) x (4m) + (3l) x (5n)
= 3l² -12lm + 15ln
Second expression = 4l(10n - 3m + 2l)
= (4l)x (I0n) - (4l) x (3m) + (4l) x (2l)
= 40ln -12lm + 8l²
On subtracting first expression from second expression, we get
40ln -12lm + 8l²
15ln - 12lm + 3l²
(-)      (+)     (-)
___________________
25ln + 0 + 5l²
___________________
= 25ln + 5l²

First expression = 2x(z - x - y)
= (2x) x z - (2x) x (x) - (2x) xy
= 2xz - 2x² - 2xy
Second expression = 2y(z - y - x)
= (2y)x(z)-(2y) x (y)-(2y)x(x)
= 2yz - 2y² - 2yx
On adding above expressions, we get
2xz - 2x² - 2xy
+              -2yx + 2yz - 2y²
_________________________
2xz - 2x² - 4xy + 2yz - 2y²
__________________________

The numerical factor of a term is called its numerical coefficient or simply coefficient. In given expressions, terms and corresponding coefficients are given in the following table

Monomial, binomial, trinomial

\(2c{ a }^{ 2 }b,\frac { 2 }{ 3 } bc{ a }^{ 2 },3{ a }^{ 2 }bc\)

Using identity (a + b) (a - b) = a²-b²
where, a = 21 and b = 11, we get
(21)² - (11)² = (21 + 11) (21 -11) = 32 x 10 = 320

\(\pm \sqrt { 41 } \)

土3

4

103\(\times\)98=  (100 + 3)(100 - 2)
= (100)² + (3 - 2)100 + [3 x (- 2)]
= 10000 + 100 - 6 = 10094

5.1 x 5.2= (5+ 0.1) (5+ 0.2)
= (5)² + (0.1 + 0.2)(5) + (0.1) (0.2)
(x + a)(x + b) = x² + (a + b)x + ab
= 25 + 1.5+ 0.02 = 26.52