Answer:
4x + 10y = 36 ≡ to 2x + 5y = 18
As you can see, the the coefficients on the first one are double those in the second.
12x - 9y = -60 ≡ to -4x + 3y = 20
In this case, the terms in the first one are all the same, but multiplied by -3
And by simple elimination we can say:
-24x - 8y = 40 ≡ -6x - 2y = 10
In this case, the terms of the first equation are equal to those of the latter, but all multiplied by 4.
