What is the best estimate of the sum of the fractions?
31/4 +17/3 + 8/18
a) 12 1/2
b) 13
c) 14 1/2
d) 15

B) 13

Step-by-step explanation:

C) 14 1/2

Step-by-step explanation:

To find the best estimate of the sum you need to round each fraction to the nearest whole number and then add them together.

So first you need to convert 31/4 to a mixed number by dividing 31 by 4, which is 7 3/4.

Then you need to round 7 3/4 to the nearest whole number which is 8.

Then you need to convert 17/3 to a mixed number by dividing 17 by 3, which is  5 2/3.

Now you round 5 2/3 to the nearest whole number which is 6.

Then we have 8/18 so first we reduce it to its simplest form which is 4/9. 4/9 can be rounded up to 1/2.

Finally add the numbers you rounded

So, 8 + 6 + 1/2 = 14 1/2

So the best estimate of the sum is 14 1/2.

- 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

sine

step-by-step explanation: