What number replaces the ◊?

4 + 7 = 1 + 10
4 + 7 + ◊ = 1 + 10 + 8

a.
3

b.
4

c.
7

d.
8

The triangles are similar. what is the value of x? show your work.

Acar travels at an average speed of 52 miles per hour. how long does it take to travel 299 miles

If you had $1,900,000, how many days would it take you to spend all if you spent $1 a second. (there are 86,400 seconds in a day)