Question

(a+b) ×(7+4)=? then find it​

Answer 1

Answer:

(a+b)×(7+4)=(a+b)×(11)

= 11a+11b

Answer 2

Answer:

Step-by-step explanation:

a + b√3)2 = 7 + 4√3

LHS = (a + b√3)2 = a2 + 2ab√3 + (b√3)2

= a2 + 3b2 + 2ab√3

RHS = 7 + 4√3

Comparing LHS & RHS, we get

a2 + 3b2 = 7 …........(1) & 2ab√3 = 4√3 ….........(2)

From (2), a = 2/b Put this value of a in (1)

(4/b2) + 3b2 = 7 i.e. 4 + 3b4 = 7b2 or 3b4 – 7b2 + 4 = 0

3b4 – 3b2 – 7b2 + 4 = 0

(3b2 – 1) (3b2 – 1) = 0

Solving we get b = 1 or –1 or 2/\sqrt{}3 or –2/\sqrt{}3

Respective value of a = 2 or –2 or \sqrt{}3 or – \sqrt{}3 [\because a = 2/b]

hope it helps

:)