Elimination step by step for 2x+y=-2
x-2y=9

answer:

x = 1 and y = -4

Step-by-step explanation:

Multiply the second equation by -2, then add the equations together.

(2x+y=−2)

−2(x−2y=9)

Becomes:

2x+y=−2

−2x+4y=−18

Add these equations to eliminate x:

5y=−20

Then solve5y=−20for y:

5y=−20

5y

5

=

−20

5

(Divide both sides by 5)

y=−4

Now that we've found y let's plug it back in to solve for x.

Write down an original equation:

2x+y=−2

Substitute−4foryin2x+y=−2:

2x+−4=−2

2x−4+4=−2+4(Add 4 to both sides)

2x=2

2x          2

=

2             2

(Divide both sides by 2)

x=1

1 = 440

2 = 4900cm^{2}

Step-by-step explanation:

square = 280cm perimeter and area

semi circle would have radius = 70cm

perimeter of semi circle =

pi x (70x2) = 440cm

but if its with the square it would be 650cm