Question

what is the value of k if value of Dy for the equation 3x+y=1 and 2x - ky =3 is 7?​

Answer 1

Step-by-step explanation:

solve\:for\:x,\:3x+y=1\quad :\quad x=\frac{1-y}{3}solveforx,3x+y=1:x=

3

1−y

Step-by-step explanation:

\mathrm{Subtract\:}y\mathrm{\:from\:both\:sides}Subtractyfrombothsides

3x+y-y=1-y3x+y−y=1−y

3x=1-y3x=1−y

\mathrm{Divide\:both\:sides\:by\:}3Dividebothsidesby3

\frac{3x}{3}=\frac{1}{3}-\frac{y}{3}

3

3x

=

3

1

−

3

y

x=\frac{1-y}{3}x=

3

1−y

____________________________________

since,x=2

y=-3

2×2-k(-3)=3

4+k=3

k=-1