Marya plans to participate in a 20 km walk-a-thon. To prepare, she walked 4 km on Monday. She plans to increase her walk by 2 km each week until she reaches 20 km. Marya’s calculations: 4 + 2 = 6. 6 + 2 = 8. 8 + 2 = 10. 10 + 2 = 12. 12 + 2 = 14. 14 + 2 = 16. 16 + 2 = 18. 18 + 2 = 20. The equation representing Marya’s calculations is 4 + 2 w + 20. How many weeks will it take Marya to reach her goal of a 20 kilometer walk? 8 9 10 12

8 weeks

Step-by-step explanation:

20 - 4 = 16

16 / 2 = 8

answer: slight chance that it will happen

step-by-step explanation:

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.