Both define y, so they are equivalent.
5x-9=2x+6
3x-9=6
3x=15
x=5
Then plug in x into any of the equations
y=2(5)+6
y=10+6
y=16
Final answer: (5,16)
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
Answer:
20g
since mass should be in kg or gram if small then g