Hello,
Rational numbers are numbers that can be represented by fractions that consist of integers.
In this case, B. -7/3 is already a fraction that consists of integers, so it is a rational number.
C. square 3 is =

= 9, which can be represented by 9/1, so it is also a rational number.
A and D are incorrect as they cannot be represented by fractions that consist of integers.
The answers are B and C.
Hope this helps!
The ratio of 4 to 8 simplifies to 1:2. X will therefore be 3/2, as 3/2:3 simplifies to 1/2 (3 = 6/2).
To get the points at which the two boats meet we need to find the equations that model their movement:
Boat A:
vertex form of the equation is given by:
f(x)=a(x-h)^2+k
where:
(h,k) is the vertex, thus plugging our values we shall have:
f(x)=a(x-0)^2+5
f(x)=ax^2+5
when x=-10, y=0 thus
0=100a+5
a=-1/20
thus the equation is:
f(x)=-1/20x^2+5
Boat B
slope=(4-0)/(10+10)=4/20=1/5
thus the equation is:
1/5(x-10)=y-4
y=1/5x+2
thus the points where they met will be at:
1/5x+2=-1/20x^2+5
solving for x we get:
x=-10 or x=6
when x=-10, y=0
when x=6, y=3.2
Answer is (6,3.2)