Step-by-step explanation:
all you have to do is just to substitute...you have been given x= -10-15y
go to the first equation
2x+5y=35
it will be 2(-10-15y)+5y=35
work out on the brackets giving you
-20-30y+5y=35
work ouy the like terms together giving u
y=?
since you got the y term,move on to the final equation substituting y with the answer you got in the previous equation
x= -10-15(y=?)
you will get the correct value for x
