-42 decreased by 16 = -26
We are tasked to solve the value of p(8a) in the expression p(x)=3x^2-4.
This means that what would find the value of the expression when x=8a. To solve this, we simply substitute the value of x in the expression.
p(x)=3x^2-4
p(8a)=3(8a)^2-4
p(8a)=3(64a^2)-4
p(8a)=192a^2-4
To split this trinomial into two binomials, let's try and find two numbers which add to 6 and multiply to 8. To do this, we can list all the factors of 8 and then choose which factors also add to 6.
Factors of 8: (1, 8), (2, 4)
1 + 8 = 9, meaning that 1 and 8 are not the factors we are looking for. However, 2 and 4 do add to 6. By combining these numbers which an x (so that we can produce the 
term at the front of the trinomial), we find the binomials:
and 
The answer is x + 2 and x + 4.
Let no. of pens be x.
Pens : x
Pencils: x+8
Total: 2x+8
Student takes 1 pen and 5 pencils.
Remainder: 2x+8 - 5 -1 = 2x+2
2x+2 = 26
2x= 24
x = 12 (original no. of pens)
x+ 8 = 20 (original no of pencils)
There are 12 pens at first and 20 pencils.
After 1 pen is taken, 11 pens are left.
After 5 pencils are taken, 20-5=15 pencils are left.
