We are given with the rate of change of the base, db/dt equal to 1 ft/ sec and the rate of change of the height of the triangle, dh/dt equal to 2 ft/sec. b is 10 ft and h is 70 ft. Area of triangle is equal to A= 0.5 bh The rate of change of the area is equal to dA/dt = 0.5 b dh/dt + 0.5 h db/dt. Substituting, dA= 0.5*10*2 + 0.5*70 * 1 equal to 45 ft2 / sec.
They didn’t use a ruler I think they made their own materials from what they had. Also thank you.
-18 + x = -11
Let's add 18 to both sides
x = 7
Since it's a one-variable equation, it has only one solution:
25 - 4x = 15 - 3x + 10 - x
25 - 4x + x = 15 - 3x + 10
25 - 3x = 15 - 3x + 10
- 3x = 15 - 3x + 10 - 25
- 3x = 15 - 3x - 15
- 3x + 3x = 15 - 15
0 = 15 - 15
0 = 0
Hope it helped,
BioTeacher101