Question

Система 8y-x=4 и 2x-21y=2 способом подстанивки

Answer 1

Х= -4+8у
подставляем во второе уравнение получаем
-8+16у-21у=2
-5у=10
у=-2
х=-4-16=-20

Answer 2

To solve the system of equations using the substitution method, follow these steps:

Step 1: Solve one of the equations for one variable in terms of the other. Step 2: Substitute the expression from Step 1 into the other equation. Step 3: Solve the resulting equation for the remaining variable. Step 4: Use the value found in Step 3 to find the value of the other variable.

Let's solve the given system of equations:

1. 8y - x = 4
2. 2x - 21y = 2

Step 1: Solve equation (1) for x in terms of y: 8y - x = 4 x = 8y - 4

Step 2: Substitute the expression for x from Step 1 into equation (2): 2(8y - 4) - 21y = 2

Step 3: Solve the equation for y: 16y - 8 - 21y = 2 Combine like terms: -5y - 8 = 2 Add 8 to both sides: -5y = 10 Divide by -5: y = -2

Step 4: Use the value of y found in Step 3 to find the value of x: x = 8y - 4 x = 8(-2) - 4 x = -16 - 4 x = -20

So, the solution to the system of equations is x = -20 and y = -2.