Question

if a-b=7 and ab=9, then a2+b2=?​

Answer 1

Answer:

67

Step-by-step explanation:

Whenever you're solving this type of equation, always write the formula first. Now.. analyse the question properly and see which formula will be most applicable. Then.. from the question put the data accordingly into your formula.

In this case, the formula which we will be using is:-- ( a--b ) ^2 = a^2 + b ^2 -- 2ab

Now..

we know that a -- b = 7, ab

After putting the values in the formula, we get:-

7^2 = a^2 + b^ 2 -- 2* 9

=) 49 = a^2 + b^2 -- 18

=) a^2 + b^2 = 49 + 18 ( Transposing the values)

Therefore,

a^2 + b^2 = 67