If you were to use the substitution method to solve the following system, choose the new equation after the expression equivalent to x from the first equation is substituted into the second equation.

x + 4y = −9
2x + 5y = −6

x=-9-4y

substitute

2(-9-4y)+5y=-6

-18-8y+5y=-6

-18-3y=-6

-3y=-6+18

-3y=12

-3y÷-3= 12÷-3

y=-4

the functions have the same rate of change i think. i narrowed it down to this answer and "the rate of change of tour 1 is greater" but i got it wrong using that answer so im assuming its the answer above. (this is a question i also answered from the iready site if anyone needs a reference)