Question

1. \

$$\begin{cases} y = 3x \\\\ x = -2y + 70 \\end{cases}$$

Explanation:

Step1: Substitute \( y = 3x \) into \( x=-2y + 70 \)

We get \( x=-2(3x)+70 \).

Step2: Simplify the equation

Expand the right - hand side: \( x=-6x + 70 \).
Add \( 6x \) to both sides: \( x + 6x=-6x+6x + 70 \), which simplifies to \( 7x = 70 \).
Divide both sides by 7: \( x=\frac{70}{7}=10 \).

Step3: Find the value of \( y \)

Substitute \( x = 10 \) into \( y = 3x \), we get \( y=3\times10 = 30 \).

Answer:

The solution of the system of equations is \( x = 10,y = 30 \)