Answer:
Step-by-step explanation:
we have

we know that
The sum of a quadratic equation and a linear equation will be a quadratic equation
so
Combine like terms

Answer:
Step-by-step explanation:
Answer:
At least two of the lateral faces are congruent.
Step-by-step explanation:
Because the words "at least" are used this means that at a minimum 2 of the faces are congruent. Because the base is in the shape of a triangle, this will definitely be true.
hope this helps:)
You should be able to set up a proportion between the sides something like (18+x)/x=(56+21)/56