Well u do 31.2 x 18 which is 561.6 then u divide by 2 because the formula for a triangle is base x height divided by 2 so It is 280.8
The short answer is: when their fractions add up to full integers.
For examples, two halves make up a whole, or

so the mixed numbers with those will add up to full integers:

but if they don't add up to an interger, the whole sum won't be an integer:
Answer: 32
Step-by-step explanation:
4cm × 8cm = 32cm
Answer:
t = 5 seconds h = 128 feet
Step-by-step explanation:
The given equation of the object is :
.....1
When it hits the ground,
h(t) = 0
So,

The object will hit the ground in 5 seconds.
Now, put t = 1 s in equation (1).

The object is at a height of 128 ft at 1 second.
Answer:
33
X
−
4
Step-by-step explanation: