Answer:
45
Step-by-step explanation:
You already solved that the 2 angles of the triangle are 55° and since all of the angles are on a straight line, they add up to 180°
and the equation becomes...
3x-10+55=180
3x+45=180
Subtract 45 from both sides
3x=135
Divide by 3
x= 45
Then to double check you plug 45 as the value of x in.
3(45)-10+55=180
135-10+55=180
125+55=180
180=180
 
        
             
        
        
        
Answer:
total bill=1644
let he drives x kilometer
then 
500*2+8*x=1644
1000+8x=1644
8x= 1644-1000
8x= 644
x= 644/8=80.5 km
Step-by-step explanation:
 
        
             
        
        
        
Answer:
(2*5) 3*7-1*6÷3*2+1*4÷2*5=216
 
        
                    
             
        
        
        
Answer:
3.08 x 10^-3
Step-by-step explanation:
when putting into  scientific notation, you must make it to where there is one number to the left of the decimal. If you move the decimal left, it equals a negative power, if you move it right, it equals a positive power.
 
        
             
        
        
        
a. The first part asks for how many ways they can be seated together in a row. Therefore we want the permutations of the set of 6 people, or 6 factorial,
6! = 6 
 5 
= 30 
 4 
= 360 
 2 = 720 possible ways to order 6 people in a row
b. There are two cases to consider here. If the doctor were to sit in the left - most seat, or the right - most seat. In either case there would be 5 people remaining, and hence 5! possible ways to arrange themselves.
5! = 5 
 4 
= 20 
 3 
= 120 
 1 = 120 possible ways to arrange themselves if the doctor were to sit in either the left - most or right - most seat.
In either case there are 120 ways, so 120 + 120 = Total of 240 arrangements among the 6 people if the doctor sits in the aisle seat ( leftmost or rightmost seat )
c. With each husband on the left, there are 3 people left, all women, that we have to consider here. 
3!  = 3 
 2 6 ways to arrange 3 couples in a row, the husband always to the left