Question

Which one of these strategies would eliminate a variable in the system of equations 8x+5y=-7, -7x+6y=-4

Answer 1

Answer: Multiply the top equation by 6, multiply the bottom equation by -5, then add the equations

Explanation:

Answer 2

For this case we have the following system of equations:

`8x + 5y = -7\\-7x + 6y = -4`

If we want to solve the system by the "elimination" method, we must multiply some (or two) of the equations by a number such that when one is added, one of the variables is eliminated.

Multiplying by 6 the first equation we have:

`48x + 30y = -42`

Multiplying by -5 second equation we have:

`35x-30y = 20`

If we add both equations, the variable y is eliminated.

We can also multiply the first equation by 7:

`56x + 35y = -49`

We multiply the second equation by 8:

`-56x + 48y = -32`

Adding the equations eliminates the variable x.

Answer:

One strategy may be to multiply the first equation by 7, the second equation by 8 and add.