X/y= -7/4 và 4x -5y =72

To solve this system of equations, we can use the method of substitution.

First, let's solve the first equation for x:

x/y = -7/4

Multiply both sides of the equation by y:

x = (-7/4)y

Now substitute this expression for x in the second equation:

4x - 5y = 72

4((-7/4)y) - 5y = 72

-7y - 5y = 72

-12y = 72

Divide both sides of the equation by -12:

y = -6

Now substitute this value of y back into the first equation to solve for x:

x/y = -7/4

x/(-6) = -7/4

Multiply both sides of the equation by -6:

x = (-7/4)(-6)

x = 21/2

So the solution to the system of equations is x = 21/2 and y = -6.