Help please?thank u

BC ≈ 21 units

Step-by-step explanation:

This problem cannot use the Pythagorean theorem as it is not a right triangle. However, you can use the law of cosines, which states that the formula works for any triangle (given that a, b and c are sides of a triangle and the angle c is opposite vertices C)

In this case, a and b can be replaced with 12 and 15 respectively, and angle c is 105 degrees.

the cosine of 105 degrees is about -0.25882 rounded to the 5th decimal place

After the difference, you should end up with BC^2 and by taking its root, you should end up with about 21.49825 or rounded to the nearest whole number, 21.

Hope this helps : )

sas (side angle side)

aa (angle angle)

sss(side side side)

sas find two sides with an angle in between

aa is finding two angles and the third will add up to 180

sss find all sides

step-by-step explanation:

2(2x + 3) = -4 + 2(2x + 5)

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 6

4x - 6 + 6 = 4x - 6 + 6

4x = 4x

x = x

unlimited solutions.