if the time is 8:50 and sally needs to go to a class at 10:30 how many hours and minutes will she need to put in a timer to remind her?

She can do 9:30 to 10:15!

Step-by-step explanation:

Helping out!

It is 8:50, 10 minutes before 9:00.

From 9:00 to 10:00 is 60 minutes, or one hour.

10:00 to 10:30 is 30 minutes.

So, take all of the minutes you figured out and add them.

10+60+30=100

One hour is 60 minutes, so if we subtract that from 100 minutes (100-60) we are left with 40 minutes.

Of course, this is an exact timing. If she wants to arrive 15 minutes earlier,

100-15=85

85-60=25

So, then she could put a timer for 1 hr 25 mins.

Therefore, Sally must put a timer for 1 hour and 40 minutes, if she wants the exact time of the class.

Hope this helps.

a.   we have two

lines:   y = 4-x   and  

y = 8-x^-1

given two simultaneous equations that are both to be

true, then the solution is the points where the lines cross. the intersection is

where the two equations are equal. therefore the solution that works for both

equations is when

4-x = 8-x^-1

this is where the two lines will cross and that is the

common point that satisfies both equations.

b.   4-x = 8-x^-1

  x           4-x       8-x^-1

-3           7        

8.33

-2           6         8.5

-1           5         9

  0           4        

-

  1           3        

7

  2           2        

7.5

  3           1         7.67

the table shows that none of the x values from -3 to 3 is

the solution because in no case does

4-x = 8-x^-1

to find the solution we need to rearrange the equation to

find for x:

4-x = 8-x^-1

multiply both sides with x:

4x-x^2 = 8x-1

x^2+4x-1=0

x= -4.236, 0.236

therefore there are two points that satisfies the

equation.

find y:  

x=-4.236

y = 4-x   = 4 – (-4.236)

= 8.236

y = 8-x^-1 =   .236)^-1

= 8.236

x=0.236

  y = 4-x   = 4 – (0.236) = 3.764

y = 8-x^-1 =   8-(0.236)^-1

= 3.764

thus the two lines cross at 2 points:

(-4.236, 8.236) & (0.236, 3.764)

c.   to solve

graphically the equation 4-x = 8-x^-1

we would graph both lines: y = 4-x   and   y

= 8-x^-1

the point on the graph where the lines cross is the

solution to the system of equations.

just graph the points on part b on a cartesian coordinate

system and extend the two lines.   the

solution is, as stated, the point where the two lines cross on the graph.

step-by-step explanation:

mark brainliest!