Thomas W. answered • 03/05/13
Effective Economics, Math, Finance, & Statistics Tutor
Solve for X and Y:
Since we're dealing with 3 equations that are all equal to each other we can write them either together, side by side, or separately in a series.
-6x + 5y = -10
16x + 4y = -10
We need to isolate one of the variable so we can then solve for the other variable. Let's isolate Y from the first equation.
5y = -10 + 6x (added 6x to both sides)
y = -2 + (6/5)x (divided both sides by 2) (now plug Y into the second equation to solve for X)
16x + 4*(-2 + (6/5)x) = -10 (distribute by multiplying)
16x + (-8) + (24/5)x = -10 (simplify and combine like terms) (LCD = 5 for adding the X variables)
(80/5)x - 8 + (24/5)x = -10
(104/5)x - 8 = -10 (add 8 to both sides)
(104/5)x = -2 (multiply by 5 then divide by 104)
answer: x = -10/104 = -5/52 (now plug X back into first equation)
-6*(-5/52) + 5y = -10 (simplify)
30/52 + 5y = -10 (subtract 30/52 and simplify) (LCD = 52)
5y = -520/52 - 30/52 = -550/52 (divide both sides by 5)
answer: y = -550/260 = -55/26
