Biruk wants to buy a book for $15.25 and a book for $4.85. he wants to pay with one $20 bill. use estimation to decide if this is reasonable. explain to what place value to round for an estimate that is useful in this situation.

It's not reasonable.

Step-by-step explanation:

Hi, to answer this question we have to add both book’s prices:

15.25 + 4.85 = $20.1

If he wants to pay with one $20 bill, it wouldn’t be reasonable, because:

20 <20.1

For an useful estimate, estimate to the nearest tenth:

15.30 +4.90 = 20.2

Still, he can’t afford the books because he is lacking 20 cents.

Feel free to ask for more if needed or if you did not understand something.

6mm^3 or .6cm^3

      216

      /   \

  36     6

  /   \     /

6     6   6

factor trees are nice.

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116