Answer: $0.58
<u>Step-by-step explanation:</u>
Let x represent pencil and y represent eraser
10x + 7y = 4.23 → 1(10x + 7y = 4.23) → 10x + 7y = 4.23
3x + y = 0.95 → -3(3x + y = 0.95) → <u>-21x - 7y</u> =<u> -6.65 </u>
-11x = -2.42
<u>÷-11 </u> <u>÷-11 </u>
x = 0.22
3x + y = 0.95
3(0.22) + y = 0.95
0.66 + y = 0.95
y = 0.29
2y = 2(0.29) = 0.58
Answer:
Here we have the function:
S(t) = 500 - 400*t^(-1)
Then the rate of change at the value t, will be:
S'(t) = dS(t)/dt
This differentiation will be:
S'(t) = -400/t^2
Then:
a) the rate of change at t = 1 is:
S'(1) = -400/1^2 = -400
The rate of change after one year is -400
b) t = 10
S'(10) = -400/10^2 = -400/100 = -4
The rate of change after 10 years is -4, it reduced as the years passed, as expected.
B. 4
Explanation: We are trying to find the square root of x, which is equal to 16. Meaning x has to multiply itself once to equal 16. 4 multiplied by 4 equals 16. Giving us our answer, x= 4