How do you solve the simultaneous equations #4x + y = -1# and #4x - 3y = 7#?

Question

5028 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-20T17:45:59

#x = 1/4 and y = -2#

#4x + y = -1 - - - eqn1#

#4x - 3y = 7 - - - eqn2#

Subtracting #eqn2# from #eqn1#

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

#0 + y + 3y = -8#

#4y = -8#

#y = - 8/4#

#y = -2#

Substiting the value of #y# into #eqn1#

#4x + y = -1 - - - eqn1#

#4x + (-2) = -1#

#4x - 2 = -1#

#4x = -1 + 2#

#4x = 1#

#x = 1/4#

Therefore;

#x = 1/4 and y = -2#