Problem: 8+3 (2x-4) work: 11 (2x-4)

22x-44

where did i mess up and how can i prevent from this happening again

6x - 4

Step-by-step explanation:

You messed up from the start.

You added 8 + 3 which gave you 11 and you distributed 11 to 2x and 4. (wrong)

What you were supposed to do was distrubute 3 to 2x and -4 which gives you 6x-12 then you add 8 which gives you 8+6x-12

When you simplify 8+6x-12 you get 6x-4 (answer)

You can prevent this next time by following the orders of PEMDAS

P in pemdas means parenthesis which is what you should have done first.

2nd one in the first row is correct

- "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."