Question

PLEASE HELP
Which of the following systems of equations has infinitely many solutions?
3x + 3y = 11; 6y = 6x - 22
8x - 7 = 6y; 12y - 14 = 4x
7y = x + 3; -3x + 21y = 9
5x + 7y = 4; 14y = 10x + 8

Answer 1

anything parrallel has infinite solutions. Parallel and lay on top of eachother.

Answer 2

so iuld be the first one?

Answer 3

nope. to be parallel their gradients must be the same.
arrange the eqn in the form \[ax+by+c=0\]
then, \[gradient(m)=-a/b\]
now try for the answer

Answer 4

so the third?

Answer 5

if timo86m is correct. third one z da answer.

Answer 6

do u thinlk im right?

Answer 7

not paralell, but same slope and intercepts

Answer 8

so its the third poone right

Answer 9

im not sure abt tht parellel thing. wait Il ask sm 1

Answer 10

spose one equation is a scaled version of the other, they are then equal by all accounts

Answer 11

ax+by = c ::: n(ax + by = c)

Answer 12

haha so the third one? cause thats what i keep getting

Answer 13

yep. da third one z da nly possible answer.

Answer 14

lets see


(7y = x + 3) *3
-3x + 21y = 9



21y = 3x + 9
-3x + 21y = 9


i like it