I hope that 2-1 means 21.
DE + EF = DF
4x + 10 + 21 = 9x - 15
4x + 31 = 9x - 15
31 = 9x - 4x - 15
31 = 5x - 15
46 = 5x
x = 9 1/5 = 9.2
You want 9x - 15
9*9.2 - 15
82.8 - 15
67.8 <<<<< answer.
If I have given the wrong meaning to 2-1 (which could mean 1) leave another note and I will correct my work.
Answer:
12
Step-by-step explanation:
5+7=12
5 have 7-14
7 have 15-22
The final answer is 12
Answer:
AB // CD and AD // BC, then ABCD is a parallelogram
Step-by-step explanation:
Step 2: Show AD // BC
A = (-3 , 3) and D = (0 , 0)
Find the slope of AD

B = (2 , 5) and C = (5 , 2)

The slope of AD = the slope of BC
So AD // BC because they have the same slope
Step 3:
Each two opposite sides are parallel in quadrilateral ABCD
So the quadrilateral is a parallelogram
Try looking up the answer
Answer:
0 <=t<=21
Step-by-step explanation:
Projectile is Moving upwards on an interval of (0 to 21), if we plot Velocity vs Time and denote positive y-axis above 0 and negative y-axis below 0(for velocity), then from 0 to 21 t projectile is moving upwards and has positive velocity, when the projectile reaches the top of it's motion and returns back down to ground it's velocity is negative and is plotted below the y =0 (note that is for t > 21).
hence for the interval 0 <=t <=21 the instantaneous velocity is positive (Note, instantaneous velocity is also the derivative of the velocity or the slope ).