(x - y = -3
3. (2x + y = 12

this is for solving linear systems by substitution i can’t figure it out

The solution for x – y = - 3 and 2x + y = 12 by solving linear systems by substitution is (x, y) = (3, 6)

Solution:

Given, two system of equations are x – y = - 3 ⇒ (1)

And 2x + y = 12 ⇒ (2)

We have to solve the given system of equations by substitution method.

Now, we can write (1) as x – y = - 3 ⇒ x = y – 3  

Then, substitute x value in (2)

(2) ⇒ 2(y – 3) + y = 12

⇒ 2y – 6 + y = 12

⇒ 2y + y = 12 + 6

⇒ 3y = 18

⇒ y = 6

So, substitute y value in (1) ⇒ x – 6 = - 3

⇒ x = 6 – 3

⇒ x = 3

Hence, the solution of system of equations is (x, y) = (3, 6)

f(x) is going down by 4

step-by-step explanation:

(its either that or its going left by 4)

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.