Answer: 7
Step-by-step explanation: Cross multiply, so 15 times x and 21 times 5. 21 times 5 is 105 then you divide by 15 which gives you 7.

Putting the value of Y = 15

So, X = 200
Answer:
672
Step-by-step explanation:
V=LWH
V=12*7*8
V=672
Step-by-step explanation:
Four bought a book at $6
4 x $6 = $24
8 x $x = $8x
Expression
$24 + $8x
6.2 is not a whole number
150/3 = 50 = a whole number
25 and 13 are whole numbers.