How do you solve the system of equations #-5x - 8y = 1# and #4x - 4y = - 6#?

1 Answer
Mar 15, 2018

#color(green)(x = -1, y = 1/2#

Explanation:

#-5x - 8y = 1# or

#5x + 8y = -1# Eqn (1)

#4x - 4y = -6# or

#8x - 8y = -12# Eqn (2), multiplying both sides by 2.

Adding equations (1), (2),

#5x + 8x +cancel( 8y) - cancel(8y) = -1 + (-12) #

#13x = -13# or #color(blue)(x = -1#

Substituting value of x in Eqn (1),

#-5 + 8y = -1#

#8y = -1 + 5 = 4# or #color(blue)(y = (1/2)#