Iam giving 10 points to whoever completes these answers correctly

1.y = –3x + 6
y = 9
what is the solution to the system of equations?

a.(–21, 9)
b.(9, –21)
c.(–1, 9)
d.(9, –1)

2.what is the solution to the system of equations?
y=2/3x+3
x=-2

- 15/2)
,5/3)
,11/6)
,13/3)

3.what is the solution to the system of equations?
y=1/3x-10
2x+y=4

a.(–8, 6)
b.(–6, 16)
c.(6, –8)
d.(16, –6)

4.ernesto tried to determine the solution for the system of equations using substitution. his work is shown below.

x – y = 7

3x – 2y = 8

step 1: x = y + 7
step 2: 3(y + 7) – 2y = 8
step 3: 3y + 7 – 2y = 8
step 4: y + 7 = 8
step 5: y = 1

in which step did ernesto make the first error?

a.step 1
b.step 2
c.step 3
d.step 4

Part 1) we have

------> equation A

------> equation B

Equate equation A and equation B

 

Solve for x

 

 

the solution is the point

therefore

the answer part 1) is the option C

Part 2) we have

------> equation A

------> equation B

Substitute equation B in equation A

the solution is the point

therefore

the answer Part 2) is the option B

Part 3) we have

------> equation A

------> equation B

Substitute equation A in equation B

 

 

 

Find the value of y

the solution is the point

therefore

the answer Part 3) is the option C

Part 4) we have

------> equation A

------> equation B

Step 1

Isolate the variable x in the equation A

-------> new equation A

Step 2

Substitute the new equation A in the equation B

Step 3

Solve for y

------> In this step Ernesto make the first error

Step 4

Combine like terms in the left side

 

Step 5

Subtract both sides

 

 

therefore

the answer Part 4) is the option C

Step 3

Equation for length:
L=3w-35

By inputting this into the equation to find the perimeter we get:
2(3w-35)+2w=190
Distribute
6w-70+2w=190
Add like terms
8w=260
Divide both sides by 8
w=32.5
The width is 32.5cm

To find the length input w into the equation for length
L=3(32.5)-35
L=97.5-35
L=62.5
The length is 62.5cm

Check that the solution is correct by inputting the solutions to the perimeter equation

2L+2w=190
2(62.5)+2(32.5)=190
125+65=190
190=190

I hope this helps :)