У = 4х – 1 у = 2х – 5 How do you solve this, by using substitution?!

Mathematics

1 answer:

solmaris [256]3 years ago

7 0

Answer:

x = -2, y = -9

Step-by-step explanation:

You can substitute the value of y into y. The first equation shows that y is equal to 4x -1, so we can switch this with the y in the second equation.

y = 2x -5 will become

4x - 1 = 2x - 5

Add 5 to both sides

4x + 4 = 2x

Subtract 4x from both sides

4 = -2x

Divide both sides by -2

-2 = x

Now we plug this number into an equation to find y.

y = 4x - 1 becomes

y = 4(-2) - 1

Simplifying it, we have:

y = -8 - 1

y = -9

You might be interested in

The sum of two numbers is 75. The second number is 3 less than twice the first

Mandarinka [93]

Answer:

$\large{\textbf{The two numbers are: 26 and 49}.\\}$

Step-by-step explanation:

$\large{\textup{assume the two numbers are $x$ and $y$.}}\\\large{\textup{The given sentences are written in mathematical terms as follows:}\\$$ x + y = 75 \hspace{25mm} (1)$$ $$ y = 2x - 3 \hspace{25mm} (2) $$ \\\textup{Substituting $(2)$ in $(1)$,}\\\begin{align*} & \implies x + 2x - 3 = 75 \\& \implies 3x = 78 \\& \implies x = 26\end{align*}\textup{Substituting $x$ in $(1), \hspace{5mm} y = 49$} }$