Question

Which ordered pairs in the form  (x, y) are solutions to the equation 7x−5y=28 ?Solation 7x−5y=28 ? A. (−6, −14) B. (7,9) C. (4,10) D.(-1,-7)

Answer 1

Probe every pair:

pair                 x          y           7x - 5y

A. (-6,-14)      -6       -14          7(-6) - 5(-14) = -42 + 70 = 28 => it is a solution

B. (7,9)           7          9          7(7) - 5(9) = 49 - 45 = 4 => not a solution

C. (4,10)        4          10        7(4) - 5(10) = 28 - 50 = - 22 => not a solution

C. (-1,-7)        -1          -7       7(-1) - 5(-7) = -7 + 35 = 28 => it is a solution

Answer: option A. (-6,-14) and option D. (-1,-7)