Question

x+5y=0 4x -y=21 mee ajudaaaaa

Answer 1

x = -5y
-------------------------
4(-5y) - y = 21
-20y - y = 21
-21y = 21
21y = -21
y = -21/21
y = -1
------------------------
x = -5y
x = -5(-1)
x = 5

Answer 2

x + 5y = 0>>>>>>>>x = - 5y ******  substitui  na de baixo

4x - y = 21
4 ( -5y ) - y  = 21
-20y  - y  = 21
-21y  = 21
21y = -21
y = -21/21 = -1 *****

x = - 5 ( -1)
x = + 5 ***