Solve the following system of equations. Express your answer as an ordered pair in the format (a,b). 3x+4y=17 -4x-7y=-18

Respuesta :

Answer:

Step-by-step explanation:

3x+4y = 17 _______ equation 1

-4x -7y= -18 _______ equation 2

muliply by 4 in equation 1

12x + 16y = 68 ______ equation 3

multiply by 3 in equation 2

-12x - 21y = -54 ________ equation 4

add equation 3 & 4

- 5y = 14

y = - 14/5

substitute y in equation 1

3x + 4 (-14/5) =17

3x = 17+ (56/5)

3x =( 85 + 56) / 5

3x = 141/5

x = 47/5

hence (a,b) = (47/5, -14/5)