How do you solve the following system of equations?: #10x – 30y = -1, 2x + y = 8 #?

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Answer 1 · 2016-03-09T06:35:03

#x=239/70#
#y=41/35#

From the given:

#10x-30y=-1" "#first equation
#2x+y=8" "#second equation

Solve by method of substitution:
Start with the second equation

#y=8-2x#
Use this in the first equation

#10x-30y=-1" "#first equation
#10x-30(8-2x)=-1

#10x-240+60x=-1#

#70x=239#

#x=239/70#

Now use this value to solve y:
Go back to #y=8-2x#

#y=8-2(239/70)#

#y=(560-478)/70#

#y=82/70#

#y=41/35#

checking
#10x-30y=-1" "#first equation
#10(239/70)-30(41/35)=-1#

#239/7-246/7=-1#

#-7/7=-1#
#-1=-1#

checking:
#2x+y=8" "#second equation

#2(239/70)+41/35=8#

#239/35+41/35=8#
#280/35=8#

#8=8#

God bless....I hope the explanation is useful