Can someone please help me solve the system by substitution

2x=y
5x+5y=-15
(?,?)

(-1,-2)

Step-by-step explanation:

hope this helps .

the answer would be c:   ax + b = ax + c

step-by-step explanation:

answer: 5 17/33 % (to the tenth)

step-by-step explanation:

he guessed: 34.5 pounds

actual weight is 32.7

there for he is off:

34.5 -32.7 = 1.8

32.7 is the 100%

1.8 represents %? of 32.7

therefore:

32.7   - 100%

1.8     -     x%

x= 1.8*100%/32.7% = 18*100%/327%

x=1800%/327%   = (5 165/327)%

to the tenth:

5 17/33 %