201. X² -1 /X +
1 = 4 (X + 1 ) (X -1) /X + 1 =
4 - 1 = 4
X = 5.
202. If a = 3
2/3,b = 2 ½, C = 4 ¾, D = 3 1/3, then
Given exp. = (a² - b²) / (c² -d²) + (a – c) / (c – d) = (a² - b²) /
(c² -d²) x (c – d) /(a – b) = (a + b) / (c + d)
= 3 2/3 + 2 ½
4 3/4 + 3 1/3 = 11/3 + 5/2
/ 19/4 + 10/3 = 37 / 6 x 12 / 97 = 74 / 97.
203. .
Given exp. = a² - b² / a + b = a – b = (1 + 1 / 1 _ 1/100 ) – (1 - 1/ 1 + 100)
= 2 x 1/ (101 / 100) = 2 x 100 / 101 = 2 x 100 / 101 =
200 /101.
204. (a
+ b +c) ²=
a²
+ b²
+ c²
+ 2 (a b + b c + ca)
2 (a b + b c + ca) =(a + b + c)²= 169 – 69 = 100.
A b + b c + ca = 50.
205. Given
: X² + y² + z² - 64 = -2 ( x y - y z – z x )
Now, [X + y + (-z)] ²= X ²
+ y² + z² + 2 (x y – y z – z x)
(3z – z)² = x² + y² + z²) – + 2 (x y – y z – z x)
- 2 (x y – y
z – z x) = (X² + y² = z²) – (2z)²
From (I) and (II), we get: (2z)² = 64 4z² = 64 z² = 16
Z = 4.
