Solve system of linear equation by substitution -x+y=2; 3x-5y=-4

(-3,-1)

Step-by-step explanation:

-x+y=2

3x-5y=-4

in the top equation, we can get y by itself on one side of the equation:

-x+y=2

y=x+2

now, since we know that y=x+2, in the bottom equation we can substitute x+2 for y (substitution method) and solve:

3x-5y=-4

3x-5(x+2)=-4

3x-5x-10=-4

-2x-10=-4

-2x=6

x=-3

since we now know that x=-3, we can use it to find y by plugging in -3 for x in the top equation (you can do it in either equation, but doing it in the top equation is easier):

y=x+2

y=-3+2

y=-1

(-3, -1)

259.05 sq. ft.

Step-by-step explanation:

The quantity of paint used will be equal to the total surface area of the fence posts.

Since the wooden poles can be represented by closed cylinders geometrically, the Total Surface Area is

2πrh + 2πr^2

r = radius of post = 0.5 feet

T. S. A =

2 x 3.14 x 0.5 x 7 + 2 x 3.14 x 0.5^2

= 23.55 sq ft.

Since there are 11 fence posts, the total surface area will be multiplied by 11

= 23.55 x 11 = 259.05 sq. ft.

Therefore, the quantity of paint will be equal to the total surface area of the fence posts.