How do you solve the following system: #x - 3y = -1 , 4x+y=-7 #?

2 Answers
Apr 8, 2018

Answer:

#x=-22/13#
#y= -9/39#

Explanation:

# x - 3y = -1#
# 3(4x + y = -7)#

#x-3y = -1#
#12x+3y = -21#

# 13x = -22#
#x = (-22/13)#

#(-22/13) - 3y = -1#
#-1 + 22/13 = -3y#
#(-13+22)/13 = -3y#
#9/13 *1/-3 = y#
#y= -(9/39)#

Apr 8, 2018

Answer:

#x=-22/13#
#y=-3/13#

Explanation:

#x-3y=-1# --- (1)
#4x+y=-7# --- (2)

From (1),

#x=3y-1# --- (3)

Sub (3) into (2)

#4(3y-1)+y=-7#
#12y-4+y=-7#
#13y=-3#
#y=-3/13# --- (4)

Sub (4) into (3)

#x=3(-3/13)-1#
#x=-22/13#