Question

A student is trying to solve the set of two equations given below:

Equation A: x + z = 6
Equation B: 3x + 2z = 1

Which of the following is a possible step used in eliminating the z-term?

A. Multiply equation A by -2
B. Multiply equation b by 2
C.Multiply equation A by 3
D.Multiply equation b by 3

Answer 1

Think: 'If I can change one of the equations so that the coefficient of the z term is the same as the coeff. of z in the other term, except for sign, then I can add the two equations together and thus eliminate z."

Answer 2

So will it be A?

Answer 3

Did you see the "except for sign" in my previous comment?

Answer 4

yes but im still a little confused

Answer 5

if I get it wrong I get it wrong thanks any way though

Answer 6

The goal here is to eliminate z.

What is -2z + 2z ?
What is 2x - 2z?

How can you change the first equation so that z will cancel out from this system of two equations?

Answer 7

- 2z ?

Answer 8

ITS OK

Answer 9

Multiply the first equation bhy -2. No point in multiplying it by -2z, because z already appears in the equation. So, now, can you select the correct answer?