(-6x3-4x2-8)+(x3-x2-9x+4) add together and simply

-5x³ -5x² -9x - 4

Step-by-step explanation:

(-6x³-4x²-8)+(x³-x²-9x+4)

Add the like terms.

-6x³ and x³ are like terms. -6x³ + x³ = -5x³

-4x² and -x² are like terms. -4x² - x² = -5x²

-8 and 4 are like terms. -8 + 4 = -4

-6x³-4x²-8 +x³-x²-9x+4 = -5x³ -5x² -9x - 4

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet

mark brainliest

step-by-step explanation:

2 tens + 6 ones

1 ten + 16 ones

0 tens + 26 ones