How do you solve the simultaneous equations #6x + 2y = 50# and #2x + 4y = 20#?

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Answer 1 · 2015-08-09T07:29:58

#{(x = 8), (y = 1) :}#

#6x + 2y = 50" " " " " "(1)#

Can be written as

#6x + 2y - 50 = 0#

#2x + 4y = 20 " " " " " (2)#

Can be written as

#2x + 4y - 20 = 0#

To eliminate #x#, let us multiply equation #(2)# by #3#; then it becomes -

#6x + 12y - 60 = 0#

Since both equations are equal to zero; we shall have them like this-

#6x + 2y - 50 = 6x + 12y - 60#

Take the unknowns to left and the constants to the right.

#cancel(6x) + 2y - cancel(6x) - 12y = - 60 + 50#

#- 10y = - 10 implies y = ((-10))/((-10)) = 1#

Substitute #y = 1# in equation #(1)#

#6x + 2 * 1 = 50#

#6x = 50 -2#

#x = 48/6 = 8#