" the sum " means add
(c + d) - 3 <== ur expression
It is d, -8.-5. I did it on paper
Answer: x= 5
Step-by-step explanation:
Plug the second equation into the first equation’s y.
3x-2(-2x+7)=21
Then use distribution
3x+4x-14=21
Add 4x and 3x
7x-14=21
Then add 14 to both sides
7x=35
Divide by 7 to get x
35/7=5
x=5
Answer: 4 years
Step-by-step explanation:
A(0) has to be amount at start. Assume that's 5mg
Then A(t) = 5×(0.5)^(0.25t) = 5×2^(-t/4),
(also known as 5 exp(-λ t) with λ = ln(2)/4, incidentally).
We need to such that A(t) = 2.5mg, or 2^(-t/4) is 1/2, which happens when -t/4 is -1, or t is 4.
Answer:
(1, 2 )
Step-by-step explanation:
Under a reflection in the x- axis
a point (x, y ) → (x, - y ), thus
C(1, - 2 ) → C'(1, 2 )