ANSWER

EXPLANATION
The given expression is

We regroup the numerical parts to get;

Now let us simplify the negative numbers.

We now subtract 19 from 42 to get;

We can't simplify further
Hence the simplest form is:

Answer:
1.25kg
Step-by-step explanation:
useing the problem the half life equation will be:
f(x)=5(0.5)^(x/140)
x is amount of days
so plugging in 280 for x will get 1.25kg
Answer:
-7,3
Step-by-step explanation:
Answer:
Y = -2X + 7
Step-by-step explanation:
Y = a(x-h)^2 + k
From (h,k) h = 0 k = 7 x = 2 y = 3
3 = a(2-0) + 7
3 = 2a - 0 + 7
Collect like terms
2a = 3 - 7
2a = -4
Divide both sides by 2
2a/2 = -4/2
a = -2
y = a(x-h) + k
y = -2(x-0) + 7
y = -2x + 0 + 7
y = -2x + 7 or
y + 2x - 7 = 0