Question 1
(a) Find the product: (3a + 8) (3a - 8)
(b) Prove that
(x-1+y)(x + y)-1= 1/xy
Question 2
(a) Solve the following equation for n:
2n+1 = 41n-8
(b) Find the value of a² + b² when a + b = 8, ab = 20
Question 3
(a) By using suitable identity, evaluate: 101 x 99
Answers
Answer:
BRO I ONLY KNOW Q1. & O3.
MARK ME AS BRAINLIEST
Q1.
a. 9a^2+6a-24a-16
9a^2-18a-16
b. 1/y-1/x∝1/x-y
Or (x-y)/xy=k×1/(x-y)(where k≠0)
Or (x-y)²=kxy
Or x²-2xy+y²=kxy
Or x²+y²=(k+2)xy
Or (x²+y²)/xy=k+2
Or x/y+y/x=k+2
Or (x/y)²+1=c(x/y) (where c=k+2 =constant)
Or (x/y)²-2(x/y)(c/2)+c²/4+1-c/4=0
Or (x/y-c/2)²=(c²/4)–1
Or x/y-c/2=±√(c²-4)/2
Or x/y=(c/2)±√(c²-4)/2
Or x/y=constant
Therefore x∝y
Q3.
101×99.
=(100+1)(100-1).
by using the property (a+b)(a-b)=a²-b²
=(100)²-1
=10000-1
=9999
answer1:
(a)3a sq-8 sq [(a+b) (a-b) =a sq-b sq]
(b)don't know
answer2:
(a)2n+1=41n-8
=8+1=41n-2n
=9=39n
=n=39/9
(b)question is wrong it must be 9 at the place 8.
answer3:
(a)(100+1)99
=9900+99
=9999