Question

Y=3x-1, 2x+y=9;Розв'яжи системурівнянь способомпідстановки.Середвiдповiдей знайдизначення Х​

Answer 1

$\displaystyle\bf\\\left \{ {{y=3x-1} \atop {2x+y=9}} \right. \\\\\\\left \{ {{y=3x-1} \atop {2x+3x-1=9}} \right. \\\\\\\left \{ {{y=3x-1} \atop {5x=9+1}} \right. \\\\\\\left \{ {{y=3x-1} \atop {5x=10}} \right. \\\\\\\left \{ {{y=3\cdot 2-1} \atop {x=2}} \right. \\\\\\\left \{ {{y=6-1} \atop {x=2}} \right. \\\\\\\left \{ {{x=2} \atop {y=5}} \right. \\\\\\Otvet \ : \ (2 \ ; \ 5) \ \ \ \boxed{x=2}$

Answer 2

Ответ:

2x+y=9

2x+3x-1=9

2x+3x=9+1

5x=10

x=10:5

x=2

Ответ: 2

Answer 3

To solve the system of equations using the method of substitution, we'll start by solving one of the equations for one variable and then substituting that expression into the other equation.

Let's solve the first equation for y: y = 3x - 1

Now we'll substitute this expression for y in the second equation: 2x + (3x - 1) = 9

Simplifying the equation: 2x + 3x - 1 = 9 5x - 1 = 9 5x = 10 x = 10/5 x = 2

Now that we have the value of x, we can substitute it back into either of the original equations to find y. Let's use the first equation: y = 3x - 1 y = 3(2) - 1 y = 6 - 1 y = 5

So the solution to the system of equations is x = 2 and y = 5.