7x+14y=-21 -3x-6y=9

Question

its a word problem

Answer 1

The first equation is equivalent to x + 2y = -3 and the 2nd equation is also equivalent to this.

 

The two equations are not different; their graphs are the same line.  So the line itself is the solution.

Answer 2

x + 2y = -3 (First equation divided by 7)

x + y   = -3 (second equation divided by -3)

Therefore x + 2y = x + y

Subtract x from both sides and 2y = y

Subtract y from both sides and y = 0

Substitute 0 into either equation for y and x = -3

The solution is the point (-3,0)

 

I don't know what 'it's a word problem' means.

Answer 3

What do you mean "It's a word problem"?

 

Both of these equations can be reduced:

 

7x + 14y = -21 All are divisible by 7 so it becomes 7[(x+2y)=-3]

 

-3x - 6y = 9   All are divisible by -3 so it becomes -3[(x+2y)=-3]

 

Hopefully this helps!