2/3 of 18...." of " means multiply
2/3 * 18 = 36/3 = 12....she has memorized 12 words so far
For the first part remember that an equilateral triangle is a triangle in which all three sides are equal & all three internal angles are each 60°. <span>So x-coordinate of R is in the middle of ST = (1/2)(2h-0) = h
And for the second </span><span> since this is an equilateral triangle the x coordinate of point R is equal to the coordinate of the midpoint of ST, which you figured out in the previous answer. Hope this works for you</span>
5x - 5y = 10
x - y = 2 . . . (1)
3x - 2y = 2 . . . (2)
(1) x 3 => 3x - 3y = 6 . . . (3)
(2) - (3) => y = -4
From (1), x - (-4) = 2
x = 2 - 4 = -2
Solution is (-2, -4)
For x = -1, 3(-1) - 5y = 9 => -3 - 5y = 9 => 5y = -3 - 9 = -12 => y = -12/5 = -2.4
for x = 0, 3(0) - 5y = 9 => -5y = 9 => y = 9/-5 = -1.8
for x = 1, 3(1) - 5y = 9 => 3 - 5y = 9 => 5y = 3 - 9 = -6 => y = -6/5 = -1.2
