Answer:
(-5.77, 6.46)
Step-by-step explanation:
15x + 9y = 45 ----------- i
9x + 8y = 12----------------ii
Multiply equation i by 9 the coefficient of x in equ ii
And equation ii by 15 the coefficient of x in equ I
9 x 15x + 9y = 45 ----------- i
15 x 9x + 8y = 12----------------ii
135x+81y = 405
135x+120y= 180
Subtract equation ii from I
135x-135x+81y-(+120y)= 405-180
-39y=225
y = 225/-39 = -5.77
Insert the value of y in equ i
15x + 9y = 45
15x+9(-5.77) = 45
15x-51.92=45
15x = 45+51.92
15x= 96.92
x = 96.92/15= 6.46
(x,y) = (-5.77, 6.46)
x = 6.92/15
(new - original)/original = mark up
(78.08-64)/64= mark up
14.08/64 =mark up
.22 = mark up
multiply by 100 to get to a percent
mark up = 22 percent
Answer: X = 2
Step-by-step explanation:
