10 pts + brainliest for the best answer

x=-5

Step-by-step explanation:

ABN + NBC = ABC

ABN = x+85   NBC = x+105     ABC = 180

Substituting these in

x+85 + x+105 = 180

Combine like terms

2x +190=108

Subtract 190 from each side

2x+190-190=180-190

2x = -10

Divide by 2

2x/2 = -10/2

x=-5

m∠ABC = m∠ABN + m∠NBC

We have m∠ABC = 180°, m∠ABN = x + 85 and m∠NBC = x + 105. substitute:

180 = (x + 85) + (x + 105)

180 = (x + x) + (85 + 105)

180 = 2x + 190       subtract 190 from both sides

-10 = 2x      divide both sides by 2

-5 = x

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5