How to solve this equation?

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Steve
Steve on 25 Jan 2015
Answered: Steve on 25 Jan 2015
Hi there,
This should be an easy question but somehow it doesn't work...
How can I solve this using matrices?
3x-2y=17 5x+3y=3
Thanks for any solutions!

Accepted Answer

Matz Johansson Bergström
Matz Johansson Bergström on 25 Jan 2015
Edited: Matz Johansson Bergström on 25 Jan 2015
This is actually very simple using the \ operator, see mldivide,\ documentation
A = [3, -2; 5, 3];
b = [17, 3]';
A\b
  1 Comment
Matz Johansson Bergström
Matz Johansson Bergström on 25 Jan 2015
Edited: Matz Johansson Bergström on 25 Jan 2015
Also, we can easily verify that it is correct
x = 0:5;
y1 = (3*x - 17)/2;
y2 = (-5*x + 3)/3;
close all
hold on
plot(x, y1, 'k', 'linewidth',2)
plot(x, y2, 'b', 'linewidth',2)
A = [3, -2; 5, 3];
b = [17, 3]';
xy = A\b % solve Ax=b for x
plot(xy(1), xy(2), 'Or', 'linewidth', 4) %the solution

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More Answers (1)

Steve
Steve on 25 Jan 2015
Great thank you! You helped me a lot! =)

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