For what values a, b is x-3y=a, 7x+3y=62 satisfied?

[Angela123]

For what numbers a and b is the system of equations below satisfied by x=b and y=a?

x-3y =a
7x+3y =62

I have no idea how to solve this, except for if I was to cancel out the y's and then I'd have 8x=a+62, but then what?

 

[stapel]

For what numbers a and b is the system of equations below satisfied by x=b and y=a?

x-3y =a
7x+3y =62

Since y = a, then the system is actually:

. . . . .1x - 3y = 1y
. . . . .7x + 3y = 62

...which adds down to give:

. . . . .8x = y + 62

As one would expect with a system of two equations in three variables, there is an infinite number of solutions.

Eliz.