If a-b=5,a²+b²=49
Find the value of a b
Answers
Answered by
18
a-b = 7
a2+b2 = 85
a3+b3 = (a+b)(a2-ab+b2)
Now,
(a-b)2 = a2+b2-2ab
49 = 85-2ab
2ab = 36
ab = 18
Now We Need To Find The Value Of a+b
(a+b)2 = a2+b2+2ab
(a+b)2 = 85+2*18 = 85+36 = 121
a+b = 11
Now Substitute It In the identity
a3+b3 = (11)(85-18)
a3+b3 = 67*11 = 737
Hope this helps you
pls mark as brainliest if helpful
a2+b2 = 85
a3+b3 = (a+b)(a2-ab+b2)
Now,
(a-b)2 = a2+b2-2ab
49 = 85-2ab
2ab = 36
ab = 18
Now We Need To Find The Value Of a+b
(a+b)2 = a2+b2+2ab
(a+b)2 = 85+2*18 = 85+36 = 121
a+b = 11
Now Substitute It In the identity
a3+b3 = (11)(85-18)
a3+b3 = 67*11 = 737
Hope this helps you
pls mark as brainliest if helpful
Answered by
45
Given
a^2+b^2=49...... (1)
a-b=5
Squaring both sides
(a-b)^2=(5)^2
a^2+b^2-2ab=25
49-2ab=25........(from1)
-2ab=25-49
-2ab=-24
ab=-24/-2
ab=12
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