Answer:
Step-by-step explanation:
<u>Sides of the picture added margin:</u>
<u>Solution</u>:
- A(margin) = Total area - A(picture)
- (8 + 2x)(5 + 2x) - 5*8 = 30
- 4x² + 10x + 16x + 40 - 40 - 30 = 0
- 4x² + 26x - 30 = 0
- 2x² + 13x - 15 = 0
- x = (-13 + √(13² + 2*4*15))/4
- x = (-13 + 17)/4
- x = 1 cm
Note. The other root is ignored as negative.
and 
use the second expression to calculate the left-hand side of the first equation:

Add 10 to both sides if this equation to get

and divide both sides by 2

this proves that x = 17, give the two initial equations
Answer:
23
Step-by-step explanation:
-26-(-49)=-26+49=23
Answer:
-3/2
Step-by-step explanation:
The rate of change is the same as slope
Answer:
C
Step-by-step explanation:
Key in the expression is "s" that represents students going to the trip
The first part shows what the adventure park is going to charge, a group day charge of $300 and $30 more for the students taking the ropes course
300+30*s
The second being the amount the class can get, $500 the have in the account and $25 per student in tickets they have to sell
500+25s
The result of this subtraction is the money they need to raise to complete
C: The expression shows how much money the freshman class may need to raise in order to afford the event