The graph shows a system of which two equations? A.) y = x - 18 and y = x + 4
B.) y = -x +18 and y = 4/3x + 4
C.) y = 18x and y = 4x
D.) y = -x + 18 and y = 3/4x + 4

y = -x + 18 and y = 3/4x + 4

Step-by-step explanation:

For the line with positive slope. Using the coordinate points (0,4) and (8, 10)

Slope m = 10-4/8-0

m = 6/8

m = 3/4

Get the intercept

Substitute m = 3/4 and (0,4) into y = mx+b

4 = 3/4(0) + b

4 = 0+b

b = 4

Get the equation;

y = 3/4 x + 4

For the line with negative slope

Using the coordinate (0,18) and (8, 10)

Slope m = 10-18/8-0

m = -8/8

m = -1

Get the intercept

Substitute m = -1 and (0,18) into y = mx+b

18 = -1(0) + b

18 = 0+b

b = 18

Get the equation;

y = -x + 18

Hence the equations are  y = -x + 18 and y = 3/4x + 4

if x decreases by 4 then y increases by 10

step-by-step explanation: