Elia is solving the following system below by substitution. {3x+y=104x−3y=−12 Which of the following would be a step in solving the system? Substitute y+10 for x in 4x−3y=−12. Substitute −y+10 for x in 4x−3y=−12 Substitute −3x+10 for y in 4x−3y=−12 Substitute 3x−10 for y in 4x−3y=−12

i would say c is the best answer, hope it's right!

good luck! =)

cutie~

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

hm let me think hm think think hm think yes