Question

Regla de cramer [4x +7y=18 2x+3y=8

Answer 1

Forma 3 matrices y sacales sus determinantes:

$A = \binom{4}{2} \binom{7}{3}$

$A1 = \binom{18}{8} \binom{7}{3}$

$A2 = \binom{4}{2} \binom{18}{8}$

...

$det(A) = 4 \times 3 - 7 \times 2$

$det(A) = - 2$

...

$det(A1) = 18 \times 3 - 8 \times 7$

$det(A1) = - 2$

...

$det(A2) = 4 \times 8 - 18 \times 2$

$det(A2) = - 4$

Por la regla de cramer:

$x = \frac{det(A1) }{det(A) }$

$y = \frac{det(A2) }{det(A)}$

...

$x = \frac{ - 2}{ - 2} = 1$

$y = \frac{ - 4}{ - 2} = 2$