Question

question 3
4x + 8y = 20
-4x + 2y = -30
(5, 3)
(-3, 5)
(1, 7)
(7, -1)

Explanation:

Step1: Label the equations

Let:
$4x + 8y = 20$ --- Equation (1)
$-4x + 2y = -30$ --- Equation (2)

Step2: Eliminate $x$ by adding equations

Add Equation (1) and Equation (2):
$$(4x + 8y) + (-4x + 2y) = 20 + (-30)$$
$$10y = -10$$

Step3: Solve for $y$

Divide both sides by 10:
$$y = \frac{-10}{10} = -1$$

Step4: Substitute $y=-1$ into Equation (1)

$$4x + 8(-1) = 20$$
$$4x - 8 = 20$$

Step5: Solve for $x$

Add 8 to both sides, then divide by 4:
$$4x = 20 + 8 = 28$$
$$x = \frac{28}{4} = 7$$

Answer:

(7, -1)