Question

if points A(4,6) and B(1,3) lie on the graph of equation ax+by=8, then find the value of a and b

Answer 1

$\textbf{Given:}$

$\text{Equation of line is ax+by=8 }$

$\text{Since (4,6) and (1,3) lie on the line,}$

$\text{4a+6b=8 \& a+3b=8}$

$2a+3b=4$.........(1)

$a+3b=8$..........(2)

$\text{Subtracting (2) from(1)}$

$\implies\boxed{\bf\,a=-4}$

$\text{put a=-4 in (2)}$

$-4+3b=8$

$3b=12$

$\boxed{\bf\,b=4}$

$\therefore\bf\,a=-4\;\&\;b=4$