Solve the system of equations by substitution

Mathematics

1 answer:

scoundrel [369]3 years ago

7 0

Answer:

(x, y) = (1, 3)

Step-by-step explanation:

given the 2 equations

x + y = 4 → (1)

y = 3x → (2)

Substitute y = 3x into (1)

x + 3x = 4

4x = 4 ( divide both sides by 4 )

x = 1

Substitute x = 1 into (2) for corresponding value of y

y = 3 × 1 = 3

solution is (1, 3 )

You might be interested in

Divide f(x) by d(x), and write a summary statement in the form indicated.

lukranit [14]

( x^4 - 4 x³ + 2 x² - 4 x + 1 ) : ( x² + 1 ) = x² - 4 x + 1
- x^4 - x²
------------------------
- 4 x³ + x² - 4 x
4 x³ + 4 x
-----------------------
x² + 1
- x² - 1
----------------
R ( x ) = 0
( x^4 - 4 x³ + 2 x² - 4 x + 1) = ( x² + 1 ) ( x² - 4 x + 1 )

3 0

3 years ago

How many real roots does a quadratic equation have if the discriminant is -3?

soldier1979 [14.2K]

$\bf \qquad \qquad \qquad \textit{discriminant of a quadratic} \\\\\\ y=\stackrel{\stackrel{a}{\downarrow }}{a}x^2\stackrel{\stackrel{b}{\downarrow }}{+b}x\stackrel{\stackrel{c}{\downarrow }}{+c} ~~~~~~~~ \stackrel{discriminant}{b^2-4ac}= \begin{cases} 0&\textit{one solution}\\ positive&\textit{two solutions}\\ negative&\stackrel{\textit{no real roots}}{\textit{no solution}}\quad \checkmark \end{cases}$