Answer:
x+ 4x + (3x+20) = 180 ( straight line)
=> 5x + 3x+20=180
=>8x=180-20
=>8x=160
therefore, x=160/8 = 80degrees
x=20
Step-by-step explanation:
Straight lines= 180
x+4x+3x+20=180
Combine like terms
8x+20=180
Subtract 20 on both sides
8x=160
Divide by 8 on both sides
