Question

Which ordered pair is a solution for the system of equations? {3x−5y=152x−y=−4 (−5, −6) (0, 3) (2, 8) (−6, −11)

Answer 1

3x-5y =15

2x-y=-4
multiply the equation by 5 and then subtract equation 2 from equation 1
so 3x-5y =15
10x-5y =-20
-7x =35 x =-5
plug in the value of x in the second equation -10 -y =-4 - y= -4 +10 y =-6
x=-5 y=-6

Answer 2

(−5, −6)

Explanation:

GIVEN :
`3x-5y = 15`

`2x-y = -4`

SOLUTION:

`3x-5y = 15` ------EQUATION 1

`2x-y = -4` ------ EQUATION 2

Now multiply the equation 2 by 5

⇒
`5(2x-y = -4)`

⇒
`10x-5y = -20` ---(a)

Now , subtract (a) from equation i.e

`3x-5y-15-(10x-5y+20) = 0`

`3x-5y-15-10x+5y-20) = 0`

`-7x-35 = 0`

`-7x=35`

`x=(35)/(-7)`

`x=-5`

put x = - 5 in equation 1 to get value of y

`3(-5)-5y = 15`

`-15-5y = 15`

`-5y = 15+15`

`-5y = 30`

`y = (30)/(-5)`

`y = -6`

Thus (x,y) =(-5,-6) is a solution.