How do you solve 5x + y = -2 and 4x + 7y = 2?
1 Answer
Explanation:
Take a look at your system of equations
#{(5x + y = -2), (4x+7y = 2) :}#
Notice that if you multiply the first equation by
This will leave you with one equation with one unknown,
#{(5x + y = -2 | * (-7)), (4x+7y = 2) :}#
#{(-35x -7y = 14), (4x+7y = 2) :}#
#stackrel("-----------------------------------------------")#
#-35x - color(red)(cancel(color(black)(7y))) + 4x + color(red)(cancel(color(black)(7y))) = 14 + 2#
#-31x = 16 implies x = 16/((-31)) = color(green)(-16/31)#
Now use this value of
#5 * (-16)/31 + y = -2#
#y = -2 + 80/31#
#y = color(green)(18/31)#