Respuesta :

Havensdivinity

Answer: -7y = 21

explanation:

x+y=2;3x−4y=27

Step: Solve x+y=2 for x:

x+y+−y=2+−y (Add -y to both sides)

x=−y+2

Step: Substitute −y+2 for x in 3x−4y=27:

3x−4y=27

3(−y+2)−4y=27

−7y+6=27 (Simplify both sides of the equation)

−7y+6+−6=27+−6 (Add -6 to both sides)

−7y=21 (answer)

AlexTrusk

first option

manipulate line 1 to

x = 2 - y

then substitute x in line to for the righthand side above

then solve towards y.