Solve by substitution:2p+7p=-19 1/2p-3q=7?

To solve the first equation by substitution, we can combine like terms:

2p + 7p = -19
9p = -19
p = -19/9
p = -2.11

Now, we can substitute the value of p into the second equation to solve for q:

1/2(-2.11) - 3q = 7
-1.055 - 3q = 7
-3q = 8.055
q = -8.055/3
q = -2.685

Therefore, the solution to the system of equations is p = -2.11 and q = -2.685.

Step 1: Solve the first equation for p.

2p + 7p = -19
9p = -19
p = -19/9

Step 2: Substitute the value of p into the second equation.

1/2p - 3q = 7
1/2(-19/9) - 3q = 7
-19/18 - 3q = 7

Step 3: Solve the second equation for q.

-3q = 7 + 19/18
-3q = 161/18
q = -161/54

Therefore, the solution is p = -19/9 and q = -161/54.