The answer is D- 14 × (2 + 5), as 14 x 2 is 28 and 14 x 5 is 70. 2 and 5 are prime numbers with no common factors, so they can't be further simplified.
So remember that GCFs are greatest common factors, or the greatest number and/or variable that divides 2 or more terms nicely (aka no decimals).
With this, you at least know that a factor of these two numbers is 7, which turns this expression to 7(4 + 10). However, what's inside the parentheses can still be factored out with a GCF of 2. So you can further factor the expression as 2 * 7(2 + 5), which can be simplified to 14(2 + 5), or D. Since 2 and 5 do not have GCFs greater than 1, that is your answer.
The volume consists of L*W*H. Since it is a cube, each measurement will be the same. The cube is 6 for Length, width, and height. The SA for the base of the box is 36cm.
1.256 is not a whole #, and it's also not an integer. An integer is basically whole #s and their opposites. The # is not irrational. 1.256 is a terminating decimal, and can be turned into a fraction. 1.256 = 1 32/125.