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

First, solve the second equation for p in terms of q:

1/2p - 3q = 7
1/2p = 3q + 7
p = 6q + 14

Now substitute this expression for p into the first equation:

2(6q + 14) + 7q = -19
12q + 28 + 7q = -19
19q + 28 = -19
19q = -47
q = -47/19

Now substitute this value of q back into the expression for p:

p = 6(-47/19) + 14
p = -282/19 + 266/19
p = -16/19

Therefore, the solution to the system of equations is p = -16/19 and q = -47/19.

Step 1: Solve one equation for one variable.

Solve the second equation for p:

```
1/2p - 3q = 7
1/2p = 3q + 7
p = 6q + 14
```

Step 2: Substitute the expression for p into the other equation.

```
2(6q + 14) + 7q = -19
12q + 28 + 7q = -19
19q = -47
```

Step 3: Solve for q.

```
q = -47 / 19 = -2.47
```

Step 4: Substitute the value of q back into the equation for p.

```
p = 6q + 14
p = 6(-2.47) + 14 = 3.53
```

Therefore, the solution to the system of equations is:

```
p = 3.53
q = -2.47
```