Question

11. If a + b = 5 and ab = 2, find (a) (a + b)2
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Answer 1

Answer:

Formula

(a+b)

2

=a

2

+b

2

+2ab

=>a

2

+b

2

=(a+b)

2

−2ab

Given, a+b=5 and ab=6

So, a

2

+b

2

=(a+b)

2

−2ab=5

2

−2×6=25−12=13

Answer 2

Step-by-step explanation:

Given :-

a+b=5 and ab=2

To find:-

(a+b)²

Solution:-

a+b=5

ab=2

a)(a+b)²=5²=25

We know that

(a+b)²=a²+2ab+b²

Substituting given values in the equation then

5²=a²+b²+2(2)

=>25=a²+b²+4

=>a²+b²=25-4

a²+b²=21

Answer:-

a) The value of (a+b)²=25

b) The value of a²+b²=21