if a+b=12 and a-b=8 then find the value of ab
Answers
Answered by
0
Answer:
ab = 10 x 2 = 20
Step-by-step explanation:
Given
a+b = 12 _____(1)
a-b = 8 ______(2)
Substracting (1) from (2)
(2) - (1): a - b - (a+b) = 8 - 12
a - b - a - b = -4
-2b = -4
b = 2
Substituting value of b in (2)
a - b = 8
a - 2 = 8
a = 8+2
a = 10
So, a = 10 and b =.2
Hence,
ab = 10x2 = 20
Checking:
(1):
LHS = a+b = 10 + 2 = 12 = RHS
(2):
LHS = a - b = 10 - 2 = 8 = RHS
Similar questions