Question

solve the following system of linear equations graphically: 3x-5y=19; 3y-7x+1=0. does the point(4,9) lie on any of the lines? if yes, write its equation

Answer 1

1.>
line 1. 3x-5y=19 &
line 2. (-7x)+3y=(-1)

now, multiplying line 1 by 3
& multiplying line 2 by 5
we get,

9x-15y=57..............line 1
(-35x)+15y=(-5)......line 2

now adding both equation
line 1 + line 2

we get,
(-26x)=52
x=(-2)
putting value of x in any of the equation we will get the value of y.

So,
x=(-2) & y=(-5)

2.>
(4,9) lie on equation 3y-7x+1=0

Answer 2

See the attach file for ans