2x+15x you can just switch the two.
7x - 4y = -28
3x +4y = -12
Using the elimination method because y is already eliminated
10x = -40
So x = -4
Then plug the -4 into the first equation....
7(-4) - 4y = -28
-28 - 4y = -28
-4y = 0
y = 0
I got: -4,0
Answer:
r = 7t
or not mathematically,
r(t) = 7t
r(t) means, r, which is a function of t.
Step-by-step explanation:
Initial size of the radius = 0 cm, at t = 0 s
Rate of increase of the radius of the circle = 7 cm/s
dr/dt = 7
dr = 7 dt
∫ dr = 7 ∫ dt
r = 7t + C (C is the constant of integration)
At t = 0, r = 0,
0 = 0 + C
C = 0
r = 7t.
r(t) = 7t
the total weight of the screws and nails is 
pounds
