Question

100 POINTS MUST SHOW WORK OR ILL REPORT!
Given

Answer 1

Opposite angles are equal

Put and equate

• 3x-20=x+40

solve

• 3x-x=40+20
• 2x=60
• x=30°

m<ABC

• 3(30)-20
• 90-20
• 70°

Option B

Answer 2

`\huge\boxed{\boxed{\mathbb{B)70°}}}`

Explanation:

to understand this

you need to know about:

• vertical angle
• equation
• PEMDAS

given:

• 
  `\sf m\angle ABC=3x-20`
• 
  `\sf m\angle DBF=x+40`

tips and formulas:

• Vertical Angles are the angles opposite each other when two lines cross
• vertical Angles are equal

let's solve:

according to the question

3x-20=x+40

=>3x-x=40+20

=>2x=60

=>x=60/2

x=30

given
`\sf m\angle ABC=3x-20`

substitute the value of x

30×30-20

simplify

90-20

70