mutshinkx mutshinkx

26-02-2021
Mathematics

contestada

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

Respuesta :

sqdancefan sqdancefan

27-02-2021

9514 1404 393

Answer:

5

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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