Barry has 18 more marbles then heidi. if barry has 92 marbles right and solve any equation to determine the number of marbles heidi has

n= Heidi's marbles

92 - n =18   (Barry's 92 marbles - whatever Heidi has = 18 marbles difference)

92 -n +n = 18 +n   (I added n to each side)

92 = 18+n    

92 -18 = 18-18 + n   (I subtracted 18 from both sides)

74 = n    Heidi has 74 marbles

Hope this helps!

you probably already have the answer but anyways it's b. 15.0

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.