You are given that all three sides are equal. You also know that all three angles are also equal. Therefore since all three angles are equal and every triangle has 180 degrees, each angle is 180/3 = 60
So
7x - 3 = 60 Add three to both sides
7x - 3 + 3 = 60 + 3 Combine
7x = 63 Divide by 7
7x/7 = 63/7
x = 9 And that's your answer.
Answer:
Step-by-step explanation:

The answer is 100!
Hope this helped!!!
(2x^2 + 4x + 6) - (-3x - 5x^2 + 4)
The negative sign separating the expressions is just multiplying the rightmost expression by -1.
(2x^2 + 4x + 6) + (3x + 5x^2 - 4)
Now, let's add together terms that share the same variable.
2x^2 + 5x^2 = 7x^2
4x + 3x = 7x
6 + (-4) = 2
Let's combine each of these terms into one expression.
7x^2 + 7x + 2 is the final answer.
First, find the surface area of the bigger sides (there are 4 of them so what you get for one you will multiply by 4)
12 x 8 = 96
96 x 4 = 384
Then find the surface area of the smaller sides ( there are two small sides so multiply your answer by two)
8 x 8 = 64
64 x 2 =128
Then add both together
128 +384 = 512
Hope this helps :)