Question

7x+3y=12; 3x+7y=6; if x and y satisfy the system of equations above, what is the value of x-y? Is the answer 3/2??

Answer 1

yes. subtract the second equation from the first one. 4 (x-y) = 6. so x-y is 3/2 !

Answer 2

the way i did it was i found a factor and elimanate both terms with x and i did it again for y ...then i sub

Answer 3

could i always do this???or no???

Answer 4

here.. this is obvious. youd generally solve the equations and then find x-y . that is how youd do it!

Answer 5

so how did you get 4(x-y)=6??

Answer 6

im studyn for the gre..grad in 08 tryn go to grad skool..ur way seems quik

Answer 7

thw equations you have here, suggest subtracting one from the other, which is why i did it. This was quick, but we only got lucky. It wont always work. It's not a "way". It just worked well here, and will most certainly not work well unless you have a nicely designed question.

Answer 8

cool..thanks..I got another question if your willin...(please lol)

Answer 9

ask it russellharris