a b 3 a 2 b 2 7 find a 4 b 4

=>(a+b)^2=9
=>a^2+b^2+2ab=9
=>7+2ab=9
=>ab=1

=>(a^2+b^2)^2
a^4+b^4+2a^2b^2=49
=>a^4+b^4=47
hence answer=47
10 years agoHelpfull: Yes(2) No(0)
since,(a^2+b^2)=(a+b)^2-2ab
so,7=9-2ab
2ab=2
ab=1
now, a^4+b^4=(a^2+b^2)^2-2(a^2)(b^2)
=49-2*1
=47
10 years agoHelpfull: Yes(1) No(0)
(a^2+b^2)^2=a^4+b^4+2a^2b^2.
(a+b)^2=a^2+b^2+2ab=> 9= 7+2ab=>2ab=2=>ab=1
so,a^4+b^4= 49-2=47.
10 years agoHelpfull: Yes(0) No(0)
Ans:10.5625
by sub x=y=3.25
10 years agoHelpfull: Yes(0) No(0)
(a+b)^2=a^2+b^2+2ab......so 9=7+2ab.....so ab=1
now a^4+b^4=(a^2+b^2)^2-2*a^2*b^2=49-2(ab)^2=49-2=47
so....a^4+b^4=47
10 years agoHelpfull: Yes(0) No(0)
a+b=3
=> (a+b)^2 = 3^2 = 9
=> a^2+b^2+2ab=9
=> 7+2ab=9
=> 2ab=2
=> ab=1
now, a^4+b^4=(a^2+b^2)^2-2(a^2)(b^2)
=49-2*1
=47
9 years agoHelpfull: Yes(0) No(0)
given: a+b=3 a^2+b^2=7
a^2+b^2=(a+b)^2-2ab; 7=(3)^2-2ab; 7=9-2ab; ab=1;
Obviously, a^4+b^4 = (a^2+b^2)^2-4a^2b^2= (7)^2-4(1)^1=49-4=45
Ans: 45
9 years agoHelpfull: Yes(0) No(0)
47
(a+b)^2=a^2+b^2+2ab from this we can calculate ab
now place this value in (a^2+b^2)^2=a^4+b^4+2(ab)^2 and we will get required result.
9 years agoHelpfull: Yes(0) No(0)
a^6+2+b^2=7
(a+b)^2-2ab=7
3^2-2ab=7
2ab=9-7
ab=1
a^4+b^4
=(a^2+b^2)^2-2*a^2*b^2
=7^2-2*1
=47.
so answer is 47
9 years agoHelpfull: Yes(0) No(0)

a+b=3 ,a^2+b^2=7 find a^4+b^4=?