Question

For each linear system,tell whether you would multiply the terms in the first or second equation in order to eliminate one of the variables.Give the number by which you could multiply.

X+3y=-14, 2x + y =-3

Answer 1

We can multiply first equation x + 3y = -14 by 2 to get rid of varibale "x"

Solution:

Given that, the system of equations are:

x + 3y = -14 ----- eqn 1

2x + y = -3 --------- eqn 2

We can solve by elimination method

For doing elimination, we have to make the any one of coefficient of variable same

Here, in eqn 1 we have 1 as coefficient for "x"

In eqn 2, we have 2 as coeficient for "x"

So, we can multiply eqn 1 by 2, to get rid of "x"

2(x + 3y = -14)

2x + 6y = -28 ------- eqn 3

If we subtract eqn 2 from eqn 3, we will get the solution

2x + 6y = -28

2x + y = -3

( - ) ----------------

5y = -25

y = -5

Substitute y = -5 in eqn 1

x + 3(-5) = -14

x -15 = -14

x = 1

Thus the solution is x = 1 and y = -5. So we have multiplied equation 1 by 2 to get of varibale "x" and solved the equations