1 mile = 1.6km.
so
100 miles x 1.6km = 160.
The number of km between two cities is 160km.
Answer:
X-42.7
Y-5.34
Step-by-step explanation:
Subtract original amount from new amount:
84 - 39 = 45
He bought 45 books.
1. Write the equation:
d(-3 + x) = kx + 9
2. "Open" the parenthesizes:
-3d + dx = kx + 9
3. Take kx to the left side, -3d to the right, everything with different sign (+ replace with - when transferring, - replace with +):
dx - kx = 9 + 3d
4. Factor x in the left side:
x(d - k) = 9 + 3d
5. Finally, divide the whole equation by (d - k):
x = (9 + 3d)/(d - k)
That's the final answer. Good luck!
