Answer:
p-q= -4
p=q-4
x^2 + px + q=0
=> x^2 + (q-4)x + q = 0
d= b^2-4ac
=(q-4)^2 - 4(1)(q)
= q^2 + 16 -8q - 4q
=q^2 -12q+16
given that D=16
q^2 -12q+16 = 16
=> q^2 -12q = 0
=> q^2 = 12q
=> q = 12q/q
=> q= 12
Therefore the value of q is 12 and the value of p is q-4 = 12-4= 8
Hope you understood............
Answer:
Try to use your calculator and just substitute values
Step-by-step explanation:

2) 5.625 mg will be left
Explanation:
1) Half-life = 17.5 days
initial amount of Arsenic-74 = 90 mg
To get the equation, we will use the equation of half-life:


2) we need to find the remaining amount of Arsenic-74 after 70 days
t = 70

So after 70 days, 5.625 mg will be left
Your answer is d hope this helps
Step-by-step explanation:
with your square root symbol I never know what is inside the square root and what is possibly outside.
so, I can only guess and see what comes close.
f(x) = 2x² + x - 1
g(x) = sqrt(2x - 1) ??? is that so ?
h(x) = -2
2g(f(x)) + h(x)
g(f(x)) means that the whole f(x) expression is used as x in g(x).
the whole combined function is then
2×sqrt(2(2x² + x - 1) - 1) - 2
2×sqrt(4x² + 2x - 2 - 1) - 2
2×sqrt(4x² + 2x - 3) - 2
and if I am not mistaken, then this is the solution you mentioned at the beginning (if I try to read between the typos and missing info).
this is how people get to this.
do you understand it now ? or is there still something unclear ?