13 + 21 = 13- -21
The minus sign and negative cancel each other out.
Answer:

Step-by-step explanation:
-10 (d+1) = -14
-10d -10 = -14
-10d = -14 + 10
-10d = -4
d = 4/10
d= 2/5
Answer:
cent/km
Step-by-step explanation:
Given


Required
The fuel cost in 
This is calculated using:




Multiply by
to get the cost in cents
cent/km
cent/km
Answer:
x = 7, arc DE = 198°
Step-by-step explanation:
Inscribed angles from the same arc are congruent.
∠ DCE and ∠ DWE are inscribed angles from the same arc DE , thus
12x + 15 = 3x + 78 ( subtract 3x from both sides )
9x + 15 = 78 ( subtract 15 from both sides )
9x = 63 ( divide both sides by 9 )
x = 7
Thus
∠ DCE = 12x + 15 = 12(7) + 15 = 84 + 15 = 99°
The inscribed angle DCE is half the measure of its intercepted arc, thus
arc DE = 2 × 99° = 198°
Answer:
B
Step-by-step explanation: