Question

2. Which values of x and y make the system of linear equations true?

4x + 7y=19
y - x= 9

A. x=-5,y=-4
B. x=-4,y=-5
C. x=5,y=4
D. x=-4,y=5

Answer 1

see below

Explanation:

attached

Answer 2

X=-4 Y= 5

Explanation:

solving the equation simultaneously

4X+7Y = 19-------------(1)

Y- X = 9-------------(2)

from equation (2),

Y = 9+X ----------------(3)

substituting equation (3) into equation (2)

4X+7(9+X)=19

removing bracket

4X+63+7X= 19

11x = 19-63

11X = -44

X= -44/11

X= -4

put X equal- 4 into equation (3)

Y= 9+-4

Y= 5

therefore, X= -4 Y = 5

therefore,

for the system of linear equation to be true, x must be= -4 and Y = 5