2 years ago

If (a+b)(a-b)=21,a+b=7 and a-b=3 what Is the value of a

Mathematics

1 answer:

topjm [15]2 years ago

8 0

9514 1404 393

Answer:

Step-by-step explanation:

Add the latter two equations and you get ...

(a +b) +(a -b) = (7) +(3)

2a = 10 . . . . . . . . . . . . . . . simplify

a = 5 . . . . . . . divide by 2

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