Can you do the grade 6 one offering 1000(promise) points for the first one to answer. iam offering this much because its a really hard one and might a take 30 min me in 3 steps

She needs to finish in 48.7 percent of the time it normally takes her

Step-by-step explanation:

6th grade math problem

swim 15 minutes 45 seconds

bike ride   45 minutes

She want to complete the 3 events in 70 minutes

swim + bike + run = 70

15 minutes 45 seconds + 45 minutes + run = 70 minutes

Combine like terms

60 minutes 45 seconds +  run = 70 minutes

Subtract 60 minutes 45 seconds from each side

60 minutes 45 seconds - 50 minutes 45 seconds +  run = 70 minutes - 60 minutes 45 seconds

run = 9 minutes 15 seconds

Her training run was 19 minutes

The percent of time she needs to take is time to finish / training run time

percent = 9 minutes 15 seconds/ 19 minutes

We need to put this in minutes.  There are 60 seconds in 1 minute

9 minutes 15 seconds =  9 minutes  15/60 = 9.25 minutes

percent = 9.25 minutes / 19 minutes

percent = .486842105

percent = 48.7 percent

She needs to finish in 48.7 percent of the time it normally takes her

- 2 + 10x³ - 21x² + 19x - 4

step-by-step explanation:

each term in the second factor is multiplied by each term in the first factor

x²(- 2x² + 4x - 1) - 3x(- 2x² + 4x - 1) + 4(- 2x² + 4x - 1) ← distribute

= - 2 + 4x³ - x² + 6x³ - 12x² + 3x -8x² + 16x - 4

collect like terms

= - 2 + 10x³ - 21x² + 19x - 4 ← in standard form