Andy and sylvie each incorrectly simplified the expression -3 - 4(2x - 3). andy wrote -14x + 21 and sylvie wrote -8 - 6. explain their errors and give the correct answer.

Given the expression -3 - 4(2x- 3) the correct solution is -8x + 9.

Step-by-step explanation:

Andy wrote -14x + 21, so his error was to do de substraction (-3 -4) and then distribute -7(2x-3) = -14x+ 21.

Sylvie wrote -8x -6. Her error was to multiplied -4 only for 2x,

then -3 - 4(2x -3) = -3 -8x -3 = -8x -6.

on friday there were 15 birds

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.