14. B (4, -2)
15. I am not exactly sure about this one but I would say either A or B.
Answer:
3.17
Step-by-step explanation:
0.45x + 0.72 + 5x = 18
5.45x = 17.28
x = 3.17
128.34
= 128+ 0.34
= 128+ 34/100
= 128+ (34/2) / (100/2)
= 128+ 17/50
= 128 17/50
128.34 written as a mixed number is 128 17/50~
Here's my interpretation: 4 whole km, plus zero tenths of a km, plus 3 hundredths of a km, plus 5 thousandths of a km.
Here, x - 2y = 14
x = 14 + 2y
Now, substitute this value into first equation,
4x + 6y = 0
4(14 + 2y) + 6y = 0
56 + 8y + 6y = 0
14y = -56
y = -56/14
y = -4
Substitute it into second equation,
x = 14 + 2(-4)
x = 14 - 8
x = 6
In short, Your Answer would be: (6, -4)
Hope this helps!