statement justification
line bc is parallel to line ed given
m∠abc = 70° given
m∠ced = 30° given
m∠abc = m∠bed corresponding angles theorem
m∠bec + m∠ced = m∠bed angle addition postulate
(missing)
m∠bec = 40° subtraction property of equality
a. m∠bec + 30° =70°; substitution property of equality
b. m∠bec + 30° = 70°; addition property of equality

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -

try quizlet : ) hope this

true

step-by-step explanation:

intersecting chords are just lines that intersect. so a line is equal to 180 degrees, so when it is intersected by another chord, then it create supplementary angles, and because the lines cross, vertical angels are also formed.