If x 12y = 210 and x  6y = 90, then x =?

answers:
Wile E. say: 1) x  12y =  210
2) x  6y = 90
Rewrite both equations in terms of x:
3) x = 12y  210
4) x = 6y + 90
Since the the right sides both equal x, then they are equal to each other (Transitive Law of Math), so
12y  210 = 6y + 90
Subtract 6y from both sides:
12y  6y  210 = 90
Add 210 to both sides:
12y  6y = 210 + 90
Combine like terms:
6y = 300
Divide both sides by 6:
y = 50
¨¨¨¨¨¨¨¨
Sub 50 for y in either of the equations, I'll choose 4):
x = 6(50) + 90
Distribute the 6:
X = 300 + 90
Combine like terms:
X = 390
¨¨¨¨¨¨¨¨¨¨¨
Solution Set (390, 50)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Idealist say: x12y=210
x6y=90

(x12y)=(210)
x6y=90

x+12y=210
x6y=90

Add them.
6y=300
y=300/6=50
Substitute.
x6(50)=90
x300=90
x=90+300=390
Answer: (390, 50)
Therefore, x=390.

David say: The solutions to the given simultaneous equations are x = 390 and y = 50

Como say: 
x  6y = 90
 x + 12y = 210_________add
6y = 300
y = 50
x  300 = 90
x = 390
x = 390 , y = 50

Φ² = Φ+1 say: x = (210×612×90)/(1×612×1) = (1260+1080)/(6+12) = 2340/6 = 390
Note: The question only asks for the solution for x.

sepia say: x  12y = 210
x  6y = 90
2x  12y = 180
x = 390, y = 50

? say: x 12y = 210
x  6y = 90
 
....6y = 300
....y = 50
x6y = 90
x = 90 + 6y
x = 90 + 6(50)
x = 390...............ANS

khalil say: multiply the second by (2) to eliminate (y)
x 12y = 210
2x +12y = 180
add
x = 390
x = 390

az_lender say: Evidently 6y = 300, so y = 50, and x = 390.

Morningfox say: The difference in those two equations is 12y  (6y) = 210  90
Which is the same as 6y = 300. I hope you can work out the rest.
