Question

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

Equation P: y + z = 6
Equation Q: 5y + 9z = 1

Which of these is a possible step used in eliminating the y-term?

(y + z = 6) ⋅ 9
(y + z = 6) ⋅ −5
(5y + 9z = 1) ⋅ 9
(5y + 9z = 1) ⋅ 5

Answer 1

so to eliminate y, you have to multiply (mostly) by a non zero number, such that, it will have the effect that your new y if added to the y in the othe equation, the result will be zero. so in this case, only -5y + 5y will eliminate y. so equation p times -5

Answer 2

it's B

Answer 3

like @MERTICH said

Answer 4

thanks(: @Johnvdb & @MERTICH

Answer 5

you are welcome!