if a-b=6 and a²+b²=48 find ab
Answers
Answer:
a + b =2
a = 2-b ……..(i)
also, ab = 2 …………….(ii)
substituting the value of (a) in equation (ii) we will have :-
(2 - b)b = 48
2b -b^2= 48
now we have a quadratic equation :-
b^2 - 2b - 48=0
now we will split -2b in such a way that on addition the result will be = -2b
also, an multiplication the product will be -48
this will be in the following way :-**#
-8b * 6b = -48b
now by spliting the quadratic equation we have:-
b^2 -8b +6b -48 =0
now by factorizing we have :-
b(b - 8) + 6(b - 8) = 0
(b+6)(b-8) = 0
b+6 = 0
b= -6
b - 8= 0
b=8
so the value of b can be 8 or -6
substituing the value of be in equation (i) we have :-
a + b = 2
a + 8 = 2
a = 2–8
a = -6
or
a -6 = 2
a = 2 + 6
a = 8
in this way value of a can be -6 or 8
so we can conclude that when value of b = 8 then a will be = -6, also when the value of b=-6 then the value of a will be = 8
hope it will help you .
thanks for reading .