You have to build an equation to find the answer,
angles in a straight line add upto 180°
so your equation would be,
12x+30°=180°
-30 -30
=12x=150°
÷12 ÷12
=x=12.5°
now find the measures of the angles by using 12.5 as x.
angle EAF= 2x
=2×12.5
=25° degrees
angle DAE= 4x
=4×12.5
=50°degrees
angle CAD=6x
=6×12.5
=75°degrees
check,
30+25+50+75=180°degrees
hope this helps.......
Answer:
20) the answer is -43
21) the answer is 25
22)the answer is -5
Step-by-step explanation:
20) 
n=-7
p=-6
we have:
21) mp-(p-(m-n))
m= -1 n=-6 p=-10
-1*-10-(-10-(-1-(-6)))
10-(-10-(5))
10-(-15)
10+15=25
22) 
m=1 n=5
1- 
1- 2/2 -5
1-1-5 =-5
The number will be itself when multiplied by 1.
The sum of twice and half the original number is 1, so the number is
2n +0.5n = 1
2.5n = 1
n = 1/2.5 = 0.4
The original number is 2/5.
