Question

a student is trying to solve the system of two equations given below:equation P: y + z = 6equation Q: 5y + 9z = 1Which of the following is a possible step used in eliminating the y-term?A: (y + z = 6) × 9B: (y + z = 6) × -5C: (5y + 9z = 1) × 9D: (5y + 9z = 1) × 5

Answer 1

we have the system

y + z = 6 ------> equation P

5y + 9z = 1 -----> equation Q

i will solve by elimination

step 1

Multiply the equation P by -5

so

(y + z = 6) *-5

-5y-5z=-30

adds equation Q

-5y-5z=-30

5y + 9z = 1

------------------

5z+9z=-30+1

therefore

the answer is the option B