During a race, a runner’s time was 4 seconds at the 36-meter mark and 6 seconds at the 57-meter mark. what was the runner’s average speed, in meters per second, for the time interval between 4 seconds and 6 seconds? (a) 2.1 (b) 9.0 (c ) 9.3 (d)9.5 (e) 10.5i need asap ):

E

Step-by-step explanation:

57 - 36 =  21              6 - 4 = 2 seconds

21 ÷ 2 = 10.5

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3