3. x+100 = 90 alternate interior angles are equal
subtract 100 from each side
x+100 - 100 = 90-100
x = -10
4. 17x+1 = 120 alternate exterior angles are equal
subtract 1 from each side
17x+ 1 -1 = 120 -1
17x = 119
divide each side by 17
17x/17 = 119
x =7
Answer:

<h3>
<em><u>x=3 or x=-10</u></em> is the right answer.</h3>
Answer:
175 is the answer
Step-by-step explanation:



Surface area will consist of:
2 triangles, 3 rectangles:
Solving for triangles:
A=1/2bh
A=1/2(120)
A=60
60*2 gives us the surface area of both triangular sides.
Solve for rectangles:
(17*20)+(8*20)+(15*20)
(340)+(160)+(300)
(800)
800+120=920
The surface area of the prism is 920 square feet
let x = the price of a book
so you would have
total = 3x-20