Step-by-step explanation:
r - 18 = 27
r = 27 + 18
r = 45
...
Although you didn't provide any answer choices:
A trinomial is an expression with exactly three terms that can't be combined an example would be this
x^2 - 3x + 1
None of those terms can be combined
x^2 + 3 - 4 has three terms but it isn't considered a trinomial because you can simplify it to x^2 - 1 which is known as a binomial because it has 2 terms in it's simplified form.
hope this helps C:
Answer:20.571
Step-by-step explanation:
x:y = 21: 24=7:8
8x=7y
y=8x/7
When x=18
y=8*18/7
y=20.571