i would appreciate any help

[kkiceman14]

i need help to figure out this problem:

1/a + 1/b = 5/7 and

ab=5, find a+b and a^2 + b^2


i would like any help i can get

 

[pka]

Well, you know that [b+a]/(ab) = 5/7. (ab)=5 so b+a = ?

 

[kkiceman14]

why is (b+a)/(ab)=5/7. I thought (1/a)+(1/b)=5/7. and ab=5

 

[stapel]

What is 1/a + 1/b, after you've converted the fractions to their common denominator and added?

Eliz.

 

[kkiceman14]

i got the answer to be a+b=25/7

 

[pka]

YES! And (a+b)<SUP>2</SUP>=a<SUP>2</SUP>+2ab+b<SUP>2</SUP>.
You now know what a+b equals and what ab equals.
Find a<SUP>2</SUP>+b<SUP>2</SUP>.

 

[kkiceman14]

i got a^2+b^2=135/49