URGENT ANSWER TO MATHS o580 p2 question NEEDED!!!

[Warrior66]

AOA, could anyone please answer this question asap because it's seriously not making any sense to me:
Q: BTW, it is a matrices question:....(^7 and 3 is down)(x y) = ((left side ^28, down 12)(right side ^42 and down is 18)). Find the values of x and y??

Thank you very much in advance...
If you still don't understand the question then:
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_2.pdf Question no. 19 b).
Thank you very much!

 

[Maya95]

I don't get it....can you send the year and question number?

 

[Warrior66]

yes I just edited it...look again...it's there at the bottom..

 

[Maya95]

Okay, so I'm really bad at explaining but I'll try my best.

Multiply the two matrices first the normal way - first row by first column, second row by second column and so on.
You'll get 7x, 7y, 3x and 3y. That matrix is equal to the one the gave you, with 28, 42, 12, and 18. Which means that 7x=28, 7y=42 and so on.
Once you've figured that out, just divide 28/7 to get x and 42/7 to get y. the answer will be x=4 and y=6.

Hope I helped.

 

[Warrior66]

Thank you Maya so very much! May Allah Bless you!! Could you also please answer another question on the same paper:
Q21. Thank you again in advance!

 

[Maya95]

I'm so sorry, I just saw this now. I'll try my best to answer it.

 

[Maya95]

Well, for part a) you have to use simultaneous equations. I think that if two lines intersect and you know both of their equations, you use simultaneous equations to find the point at which they intersect. I used this method and got the correct answer.

Do you also need part b)?

 

[Maya95]

As for b), you know that the equation of a line is always in the form y=mx+c, m being the gradient and c being the y-intercept. So to find m, you would used the formula m=y2-y1/x2-x1 and for the y intercept, you would substitute values for y and x and since you already have m, you would just used the formula y=mx+c to find c. Then you would put down the values that you've calculated in the place of m and c, and voila, you've got your answer.

 

[Maya95]

Now that I've read over my answer it seems a bit confusing. Tell me if you have any problems. Sorry for answering so late. and good luck on tomorrows exam!

 

[Warrior66]

Thank you Maya for the help.....I really appreciate it.....and sorry for replying back soo late. No..no..i understood it perfectly fine....thanks once again!!