Question

the coordinates of the points of intersection of lines ax+by=9 and bx+ay=5 is (3,minus 1). find the values of a and b

Answer 1

hope dis will help u

Answer 2

Answer:

The values of a=4 and b=3

Step-by-step explanation:

$ax+by=9$....................equation -1

$bx+ay=5$....................equation -2

At the point of intersection, the two equations will have the same values of x and y, so we rewrite the equations as

$3a+(-1)b=9\Rightarrow3a-b=9$....................equation -3

$3b-1a\Rightarrow(-a)+3b=5$....................equation -4

Now multiply the equation 4 with 3 we get

$-3a+9b=15$...................equation-5

Now add equation 3 with equation 5 we get

$(3a-b)+(-3a+9b)=9+15\\\\\Rightarrow3a-b-3a+9b=24\\\\\Rightarrow8b=24\\\\\Rightarrow{b}=3$

Put the value of b in equation 3 we get

$3a-b=9\\\\\Rightarrow3a=9+b\\\\\Rightarrow3a=9+3\\\\\Rightarrow3a=12\\\\\Rightarrow{a}=4$

The values of a=4 and b=3