Solve by addition method:?

Question

Solve by addition method:
x + 5y = 10
-2x + 20 = 10y

Answer 1

I can tell you just by looking at this that it won't work, but here's the process:
Multiply the first equation by 2 so the x coefficient in the first equation is the opposite (negative) of the x coefficient in the second equation:
2x + 10y = 20
Move the y and the constant in the second equation to make it match the formet of the first
-2x -10y = -20
Add the two equations to get:
2x + 10y = 20
+(-2x -10y = -20)
----------------------
0 = 0

There is no single solution, because the two equations are actually the same equation written differently.

Answer 2

2x + 10y = 20
-2x + 20 = 10y
10y + 20 = 20 + 10y
no solution because everything cancels out
the two lines are parallel

Answer 3

1) subtract 10y and 20 from each side of the second equation.
-2x-10y= -20
2) Divide each side of the second eq. by 2
-x-5y = -10
3)combine the 2 eq. together:
x-x+5y-5y= 10-10
0 = 0
4) the answer is R( All real numbers ) because if you substitute any number in the two equations,that number will = itself

Answer 4

With these two equations, I would multiply the bottom one by (-1), because we are trying to get one of the variables to cancel out... 2x + 5y = -1 (-2x) - (-y) = -2 ... or ... 2x + 5y = -1 -2x + y = -2 ... add the equations together... (2x - 2x) + (5y + y) = ((-1) + (-2)) ... or... 6y = -3 ... divide both sides by 6 ... y = -½ or -0.5 Now, using either original equation, insert the "y" value where there is a "y": 2x + 5(-½) = -1 ... simplify... 2x + (-(5/2) = -1 ... add (5/2) to both sides... 2x = 3/2 ... divide both sides by 2... x = ¾ Check your answers with the other equation: 2(¾) - (-½) = 2 (3/2) + ½ = 2 4/2 = 2 2 = 2 ... and the answer checks out. x = -½ and y = 01¾

Answer 5

multiplying the 1st eqn. by 2 nd adding to the 2nd eqn.
2x+10y=20
-2x+20=10y
both are one and the same equations
so infinite no of solutions

Answer 6

(x + 5y = 10) 2 = 2x+10y=20



2x+10y=20
+ -2x+20 =10y
___________
20+10y=20 +10y

er..... y=y??

Answer 7

x+5y=10
x=5
y=1

-2x+20=10y
i don't know

Answer 8

if u multiply first by
2 u get second eq
so they have infinite solutions