For example:
x+2y=7
6x+7y=2
__________
x=7-2y *
6*(7-2y)+7y=2 **
__________
x=7-2y
42-12y+7y=2
__________
x=7-2y
-5y=-40
__________
x=7-2y
y=8
x=-9
7+10x-2x-2=-3
—-Combine like terms...10x-2x=8x and 7-2=5
8x+5=-3
——subtract 5 on both sides.. the 5’s will cancel each other and -3-5=-8
8x=-8
——Divide 8 on both sides...the 8’s will cancel out and -8 divided by 8 = -1
Answer: x = -1
The 4 in 46,395 is 10 times the 4 in 14,906.