I believe it would be -17m-4/8
-2.7639320225 is the exact when estimated -3 hope this helped if can pls mark as brainliest have a great day!
Answer:

Step-by-step explanation:
Do FOIL, first outside inside last
3x × 3x = 9x^2
3x × -7 = -21x
7 × 3x = 21x
7 × -7 = -49

So it would just be 9x^2 - 49
Answer:
10
Step-by-step explanation:
This triangle is isosceles, same as the little triangle.
If one side of the little triangle is 3x, then the little side with the tick (let's name it a) is also 3x.
That means the longer side, 2a, is 6x
This triangle is isosceles, so 6x = 4x + 20
Now, if we solve that, x = 10
The answer is 10
Hope this helps :)
Have a good day!