Choose the correct simplification of 7x2(6x + 3x2 − 4). 21x4 − 42x3 + 28x2 42x4 + 21x3 − 3x2 21x4 + 42x3 − 28x2 42x4 − 13x3 + 11x2

Option (3) is correct.

Step-by-step explanation:

Given: expression

We have to write the correct simplification of the given expression

Consider the given expression

Multiply with each term in brackets  

we get,

Apply exponent rule,   and Simplify by multiply, we get,

Thus, Rearranging in standard form,  we get,

Thus, Option (3) is correct.

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3