Question

What values of x and y satisfy x + 2y = 6 and 2x + 3y = 4 simultaneously?

x = 0 and y = 3

x = 2 and y = 0

x = -10 and y = 8

x = 8 and y = -1

Answer 1

what methods do oy uknow for simulataneous equations?

x+2y=6
2x+3y= 4

Try multiplying the FIRST equation by 2

Post the new equation here

Answer 2

would it be 2x+4y=12? sorry if im wrong

Answer 3

that is correct

now the reason we multiplied by 2 is that oyu NOW have 2x in BOTH equations

2x+4y=12
2x +3y =4

SO - if oyu subtract those 2 equaitons you will 'eliminate' x

Answer 4

so would it be 1y=8?

Answer 5

yes well done

1y = 8 is th same as y=8

so there is only one possible answer

BUT if oyu want to solve for x just put y =8 into the first equation - you can then solve for x

Answer 6

u may use cramer's method too

Answer 7

There are seveal methods for simultaneous equaitons

in this case elimination was best because y=8 came straight out

Answer 8

OK - maybe not 'the best' - but very effective.

Each method has its merits

Answer 9

so the answer would be C butb if y=8 how would x=-10? if you dont mind me asking

Answer 10

@MrNood agreed :)

Answer 11

After you have solved for one of the variables (in this case y) you can just go back to either of the original equations and use that value


so in the FIRST original equaiotn:

x + 2(8) = 6

hence x

Answer 12

oh okay thanks @MrNood

Answer 13

np - you did the work yourself - I just pointed the way