Question

the co ordinates of intersection of the line ax+by =9 and bx+ay= 5 is(3,-1)find the value of a and b

Answer 1

put values of x and y

$ax + by = 9 \\ a(3) + b( - 1) = 9 \\ 3a - b = 9.............(1) \\ bx + ay = 5 \\ b(3) + a( - 1) = 5 \\ 3b - a = 5 \\ - a + 3b = 5 \\ a - 3b = - 5 ........(2) \\ adding \: equation \: 1and \: 2 \\ 3a - b = 9 \\ + a - 3b = - 5 \\ = 4a - 4b = 4 \\ a - b = 1...........(3) \\ subtrcting \: equation \: 2 \: from \: 1 \\ 3a - b = 9 \\ - a - 3b = - 5 \\ = 2a + 2b = 14 \\ a +b = 7........(4) \\ by \: soving \: equation \: 3 and \: 4 \: we \: get \\ (ab) = (43) \\ if \: you \: like \: this \: then \: plz \: add \: brainly \: list$