If this is an equilateral triangle, we need half of it to find the height which is a leg of a right triangle with a hypotenuse of 15. That means that the base of this half triangle is 7.5. Use Pythagorean's Theorem to fine the height.

. x = 12.99 or 13
Answer:
Step-by-step explanation:
(6x+1)4 = 124
6x+1 = 31
x = 5
10% of 3.99=0.399x4=1.596
1% of 3.99=0.0399x5=0.1995
1.596+0.1995=1.7955
1.8(Rounded)+3.99=5.79
M=-1/2 because you do y1-y2 over x1-x2 and end up with 2/-4 but simplified is -1/2