Question

the simultaneous equation-3x+4y=7;9/2x-6y=-21/2 have? ​

Answer 1

Answer:

x = -17/21 and y = 8/7

Step-by-step explanation:

-3x + 4y = 7

Then x = 4y-7/3

putting the value of x in equation in 9/2x-6y = -21/2

9 * 3/8y-14 - 18y = -21/2

27/-10y-14 = -21/2

27 * 2 = -21 * (-10y - 14)

54 = 210y + 294

-210y = 294 - 54

-210y = 240

y = - 240/210

y = - 24/21

y = - 8/7

putting the value of y to find x

we have x = 4y - 7/3

x = 4 * 8/7 -7/3

x = 32/7-7/3

x = 32 - 49/21

x = -17/21