Question

Como se resolve o sistema pela regra de cramer 3×+y=4 2x+5y=6

Answer 1

$\begin{cases}3x+y=4\\2x+5y=6\end{cases}$

Achando Δ:

$\Delta=\left|\begin{array}{ccc}3~~~1\\2~~~5\end{array}\right|=3\cdot5-1\cdot2=15-2=13$

Achando Δx:

$\Delta x=\left|\begin{array}{ccc}4~~~1\\6~~~5\end{array}\right|=4\cdot5-1\cdot6=20-6=14$

Achando Δy:

$\Delta y=\left|\begin{array}{ccc}3~~~4\\2~~~6\end{array}\right|=3\cdot6-4\cdot2=18-8=10$
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Achando x:

$x=\dfrac{\Delta x}{\Delta}=\dfrac{14}{13}$

Achando y:

$y=\dfrac{\Delta y}{\Delta}=\dfrac{10}{13}$