The sum of a and b is -10. the difference between a and b is 4. the product of a b and c is 40. work out the value of c.

With the data we have, we have to

A + B = - 10

A - B = 4

A . B . C = 40

We want the value of C. This is

Isolate A

A = - 10 - B

Replaces in A - B = 40, have to

- 10 - B - B = 4

- 2 B = 14

B = - 7

Replaces B

A = - 10 - ( - 7 )

A = - 10 + 7

A = - 3

like this

- 7 . ( - 3 ) . C = 40

21 . C = 40

C = 40 / 21

Hope that is helps, good studies.

none of the above.

for one of the equations to be used in the process, there has to be a term in the equation since squared is .

since there is only a term in the first equation, we cannot derive a from completing the square.

solving with completing the square