## tej18 [6.03] What is the value of the y variable in the solution to the following system of equations? 2x + y = 5 x + 3y = 0 −1 1 3 −3 one year ago one year ago

1. tej18

i really need help :0

2. abayomi12

Let x = xylophones and y = yachts. Fred is buying xylophones and yachts. He does not pay attention to how much each costs, rather he just pays for all of them in one go. When he visits the shop on Monday, he buys two xylophones and one yacht for a total price of $9. He then thanks the salesman and goes home. The next day he buys three xylophones and four yachts for a total price of$26. Fred is now deeply curious as to how much his xylophones and yachts would have cost him individually, so he sets up a set of simultaneous equations in an attempt to find an answer to the ultimate question... 2x + y = 9 3x + 4y = 26 Transpose equation 1 and substitute into 2: y = 9 - 2x 3x + 4(9 - 2x) = 26 3x + 36 - 8x = 26 -5x = -10 x = 2 y = 9 - 4 y = 5 So it turns out that xylophones cost $2 each and yachts cost$5 each. ANSWERS: 3. Parallel 4. -6 + x 8. -1 9. (9, -1) 10. Multiply the first equation by -2 11. 42 12. 22.95 + 0.08m = 27.95 + 0.06m 13. 70 14. d = 3(r – 30) and d = 2(r + 30) 15. 3 hours 16. (5, 1) 17. Green area: 2x + y > 2 and x − y < 6 Yellow area: 2x + y > 2 and x − y > 6 18. Answer shown in part 2 (very long answer)

3. mathslover

$\large{\color{red}{2x+y=5}}$ $\large{\color{blue}{\textbf{Solve for x in this eqn}}}$

4. mathslover

@tej18 what do you get after solving for x in 2x+y=5

5. sauravshakya

OMG......... what is that @abayomi12

6. tej18

ikr! @sauravshakya

7. tej18

i dont get it @mathslover

8. mathslover

2x+y=5 2x=5-y solve for x

9. tej18

ohh

10. abayomi12

teji u still don't get the answer that all the answer i just solved there

11. tej18

@mathslover so x= 5/2 - y/2??

12. mathslover

x=(5-y)/2 put this in 2nd eqn

13. mathslover

14. tej18

i m confused @mathslover

15. mathslover

$\large{x=\frac{5-y}{2}}$ $\large{x+3y=0}$ $\large{\frac{5-y}{2}+3y=0}$ $\large{\frac{5-y+2y}{2}=0}$ $\large{5+y=0}$

16. mathslover

oops sorry : $\large{\frac{5-y+6y}{2}=0}$ $\large{5+5y=0}$

17. tej18

so y=0? @mathslover

18. tej18

@mathslover

19. Kaederfds

i got y = (-1)

20. tej18

oh kk thanks! @Kaederfds

21. Sulli_lim

Answer: -1 2x+y=5 x+3y=0 So, x=-3y Substitute x=-3y into 2x+y=5 2(-3y)+y=5 -6y+y=5 -5y=5 y=-1

22. mathslover

5y=-5 y=-1 @tej18