How do solve the following linear system?: 9x + 1 = -4y, 7x - 2y - 13 = 0 ?

1 Answer
Mar 5, 2018

color(blue)(x = -62/5), color(green)(y = 27/5)

Explanation:

9x + 1 = -4y Eqn (1)

y = (9x + 1) / -4

7x - 2y = 13 Eqn (2)

Substituting value of yin Eqn (2),

7x - (2 * (9x + 1)/-4) = 13

-28x + 18x + 2 = -52

-10x = - 54 or x = 27/5

Substituting value of x in Eqn (1),

y = (9 *(27/5) + 1) / -4 = (243 + 5) / -20 = -62/5