Find mZYCD Y
21x-7
с
100° 5x+5
E
D
A) 1199
B) 140°
C) 1230
D) 40°

B)140

Step-by-step explanation:

So a line is=180 and the interior angles of a triangle= 180, so I did some manipulations

1. 100 + (5x+5) + <ECD = 180. But we also know that (21x-7) + <ECD=180. With some manipulation we can find that <ECD= 180 - (21x-7), so we can plug that into the other equation

2. Now: 100 + (5x+5) + (180- (21x-7))= 180

3. Solve:

105+5x+180-21x+7=180

112-16x=0

112=16x

x=7

4. Plug x=7 into 21x-7= 140

the multiples of 15 are 15, 30,45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195,   210, 225, 240, 255, 270, 285, 300, 315, 330, 345, 360, 375,   390, 405, 420, 435, 450, 465, 480, 495, 510, 525, 540, 555, 570, 585, 600, 615, 630, 645, 660, 675, 690, 705, 720, and 735.

the factors of 15 are 1, 3, 5, and 15.

hope that , fam!

-une, your fren : )

answer: b

step-by-step explanation: