if a+2b=5 and ab=2 find a^2+4b^2
Answers
Step-by-step explanation:
➡Given here.
↪a+2b = 5...........(1).
↪ab= 2..................(2).
➡Find here .
↪a²+4b²= ?.
➡Now,we know
♠(x+y)²= x²+2xy+y².
➡So,
▶(a+2b)²= a²+4ab +4b².
[ keep value by (2). and (1).]
♠(5)²=a²+4b²+4×2.
=> a²+4b²= 25-8.
=>a²+4b²= 17.
➡Hopes its helps u.
Answer:
Answer is 17
Step-by-step explanation:
we have
>> a+2b=5 .............(1)
>> ab=2 >> a=2/b ........(2)
>>a^2+4b^2 ..........(3)
putting (2) in (1) we got,
2/b+2b=5
2+2b^2-5b=0
by factorization we got,
b=1/2 , 2
put the values in (2) , we got
>> a=4 when b=1/2,
>> a=1 when b=2,
therefore putting values of a & b simultaneously in eq'n (3) we got
>> when a=4 , b=1/2
(4)^2+4 x (1/2)^2 = 16+1=>>17
>> when a=1 ,b=2
(1)^2+4(2)^2 = 1+16 =>>17
I hope it helps.