Solving for x on a triangle.

Question

Regular triangle model: in ABC, suppose m is less than ABD=(x 2nd power-5 degrees) and m is less than CBD=4 x degrees. Solve for x.

Answer 1

Mya, the "less than" sign isn't a "less than" sign. It's the symbol for angle. The "m" means "measure of."

The measure of angle ABD equals...

I'm guessing your two angles are congruent, or have the same measure. Set the two equal and solve for x.

x² - 5 = 4x

x2 - 4x - 5 = 0

(x - 5)(x + 1) = 0

x - 5 = 0

x = 5

x + 1 = 0

x = -1

So, we have two answers, buuuuut 4(-1) = -4 and you can't have an angle with a negative measurement. It's hard to say whether your teacher wants to get that picky, so I say the answer is x = 5 but it might be sufficient togive both since we are only told to solve for x.