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

equation p: y + z = 6
equation q: 8y + 7z = 1

which of the following is a possible step used in eliminating the y-term?
a (y + z = 6) ⋅ −8
b (y + z = 6) ⋅ 7
c (8y + 7z = 1) ⋅ 7
d (8y + 7z = 1) ⋅ 8

Option A

The possible step used in eliminating the y-term in Equation P: y + z = 6  Equation Q: 8y + 7z = 1 is (y + z = 6) ⋅ −8

SOLUTION:

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

Equation P: y + z = 6  

Equation Q: 8y + 7z = 1  

we have to find which of the given steps is a possible step used in eliminating the y-term?

We know that, while solving the system of equations, if we want to eliminate any one of the variables then, co efficient of that variable must be same in both equations but should differ by sign.

Now, let us check it.

Here coefficient of y in P is less than in Q, so let us multiply P with coefficient of y in Q and with opposite sign.

Then, (y + z = 6) . -8

Hence, the correct option is A.

there are no short passages to look at

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.