Question

Factorise:
(a)
9(a-b)²_4(a+b)?​

Answer 1

Answer:

Here a-b=8 and ab =9 so firstly we have to simplify the equation and after that find the value of a variable in terms of another and put this value in other equation

Solution:

a-b=8

a=8+b

put the value of a in another equation

(8+b)b=9

b^2+8b-9=0

b^2+9b-b-9=0

b(b+9)-1(b+9)=0

(b-9) (b+9)=0

if multiplication of two number is zero it means one of them is zero or both

So, b-9=0

b=9

or b+9=0

b=-9

so on putting value of b=9

a-b=8

a=17 and ab =9

17*9 is not equal to 9

and if we take b=-9

a-(-9)=8

a=-1

then -1*-9=9

this value of a and b satisfy the equation

So a=-1 and b=-9

then a+b = -10