Answer: 14
Step-by-step explanation: The perimeter is all of the side added together. When finding the perimeter of a rectangle the opposing sides have the same value. So the equation would be 2(12) + 2(a) = 52. 12 x 2 is 24. 52- 24 is 28 and youre left with 28 = 2(a). You divide each side by 2 and get 14 = a
The answer to the problem would be 5/7. Hope this helps.
I will only do the first-three. You can repost number 4.
Question 1
f(x) = -x^2 + 10x + 4
dy/dx = -2x + 10
Question 2
f(x) = 20 - x + 2
dy/dx = -1
Question 3
f(x) = ex^4 - 2x^2
dy/dx = e•4x^3 + x^4 - 4x
dy/dx = 4ex^3 + x^4 - 4x