SOLUTION: If a^2-b^2=70 and a-b=7, what is the value of a?

Question 388996: If a^2-b^2=70 and a-b=7, what is the value of a?
Found 4 solutions by richard1234, haileytucki, mananth, josmiceli:
Answer by richard1234(7193)   (Show Source): You can put this solution on YOUR website!
Since we can replace a-b with 7 and get

We have the system of equations and . Adding them, we obtain --> a = 17/2.
Answer by haileytucki(390)   (Show Source): You can put this solution on YOUR website!

This system of equations cannot be solved because there are more unique variables (4) than there are equations (2).
The system cannot be solved.

Can you repost this exactly how it appears? Or is there a slight error within the numbers?
Answer by mananth(16946)   (Show Source): You can put this solution on YOUR website!
If a^2-b^2=70 and a-b=7, what is the value of a?
...
a^2-b^2= 70
(a+b)(a-b)=70
a-b=7
substitute the value of a-b
(a+b)*7=70
/7
a+b=10
a-b=7
add them up
2a=17
/2
a= 17/2
b=1.5
...
Check
a^2-b^2=70
(17/2)^2-(1.5)^2 =70
...
m.ananth@hotmail.ca

Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
given:

------------

check:

OK
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