Step-by-step explanation:
Say you have these 2 fractions

Cross multiply as following;

If in the end, both numerator and denominator are equal, then the fractions are equivalent.
Examples:
Example 1

Cross multiply

They're equivalent.
Example 2

Cross multiply

They're not equivalent.
Answer: Yes this is a right triangle
We can determine this by using the converse of the pythagorean theorem.
a = 5, b = 12, c = 13

Since those a,b,c values work in the pythagorean theorem, this proves we have a right triangle.
Last one!!!!!!! its literally the opposite!!
Answer:
see explanation
Step-by-step explanation:
Note the common difference d between consecutive terms
d = 10 - 3 = 17 - 10 = 24 - 17 = 7
This means the sequence is arithmetic with n th term
= a₁ + (n - 1)d
Here a₁ = 3 and d = 7, thus explicit formula is
= 3 + 7(n - 1) = 3 + 7n - 7 = 7n - 4, thus
= (7 × 18) - 4 = 126 - 4 = 122