How do solve the following linear system?: $- 9 x + 5 y = 1, - 4 x - 15 y = - 1$ $-9x+5y=1 , -4x-15y=-1$ ?

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Answer 1 · 2018-07-02T04:57:46

$x = - \frac{2}{31}, y = \frac{13}{155}$ $color(brown)(x = -2/31, y = 13/155$

$- 9 x + 5 y = 1, Eqn (1)$ $-9x + 5y = 1, " Eqn (1)"$

$- 4 x - 15 y = - 1 Eqn (2)$ $-4x - 15y = -1 " Eqn (2)"$

Add (3 * Eqn (1) and Eqn (2)),

$3 * -9x +cancel( 3 * 5y) + -4x + cancel(-15y )= 3 *1 + -1$

$--31x = 2 " or " x = -2/31$

Substituting value of x in Eqn (2),

$(-4 * -2/31) - 15y = -1$

$-15y = -39/31$

$y = 39/ 465 = 13/155$

How do solve the following linear system?: -9x+5y=1 , -4x-15y=-1 −9x+5y=1,−4x−15y=−1 -9x+5y=1 , -4x-15y=-1 ?