if a + b = 7 and a b is equals to 10 find a minus b
Answers
Answered by
70
Given data : a + b = 7 & ab = 10
To find : a - b = ?
Answer : a - b = ± 3
Solution :
a + b = 7
Squaring both sides, we get
(a + b)² = 7²
⇒ (a - b)² + 4ab = 49
⇒ (a - b)² + 4 (10) = 49
⇒ (a - b)² = 49 - 40 = 9
⇒ (a - b)² = 3²
⇒ a - b = ± 3
Answered by
13
hère is your answer mate.....
given ab= 10
then a= 10/b
putting this value in first eq....
we get....
10/b + b = 7
multiplying This eq by b we get....
b^2 -7b + 10
factorising this.....
b^2 -5b-2b+10
b(b-5)-2(b-5)
(b-5)(b-2)
b = 5,2 ...
if b = 5 Thén à = 10/b= 10/5= 2
if b =2,then a= 10/b=10/2=5
then 1st situation
a-b = 2-5= -3
2nd situation , a-b = 5-2= 3
hope this helps you....mark as brainliest
given ab= 10
then a= 10/b
putting this value in first eq....
we get....
10/b + b = 7
multiplying This eq by b we get....
b^2 -7b + 10
factorising this.....
b^2 -5b-2b+10
b(b-5)-2(b-5)
(b-5)(b-2)
b = 5,2 ...
if b = 5 Thén à = 10/b= 10/5= 2
if b =2,then a= 10/b=10/2=5
then 1st situation
a-b = 2-5= -3
2nd situation , a-b = 5-2= 3
hope this helps you....mark as brainliest
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