Which of the following can be written as an equation A Half of a number x Half of a number x

B 3 times a number x is the same as a number y3 times a number x is the same as a number y

C A number x times the sum of 5 and 4A number x times the sum of 5 and 4

D A number y less than a number x

B

Step-by-step explanation:

"Is the same as" means an = sign, necessary for an equation!

a4 - 3a2 - 1

step-by-step explanation:

step   1   :

equation at the end of step   1   :

  ((a4) -   3a2) -   1

step   2   :

trying to factor by splitting the middle term

2.1     factoring   a4-3a2-1  

the first term is,   a4   its coefficient is   1 .

the middle term is,   -3a2   its coefficient is   -3 .

the last term, "the constant", is   -1