What is 2x+y=8 and x-2y=-1

1 answer:

4 0

The solutions of x and y?

2x+y=8...(1)
x-2y=-1...(2)
for (2), x=-1+2y...(3)
sub(3) into(1),
2(-1+2y) +y=8
-2+4y+y=8
5y=10
y=2
sub y=2 into(3)

x=-1+2(2) =3
therefore, x=3,y=2

You might be interested in

What is the solution of the system? Use a graph.<br> y = –x + 2<br> y = 3x – 1

laila [671]

-x+2=3x-1
3=4x
3/4=x

Y=3(3/4)-1
Y=(9/4)-(4/4)
Y=5/4

7 0

3 years ago

Find the unit rate for a runner in miles per hour who runs at a pace of 3/4 mile in 10minutes

yanalaym [24]

Answer:

$\large \boxed{\text{4.5 mi/h}}$

Step-by-step explanation:

A unit rate is the number of something there is per one unit of something else.

In this question, the unit rate is the number of miles per one hour.

1. Convert minutes to hours

$\text{time} = \text{10 min} \times \dfrac{\text{1 h}}{\text{60 min}} = \frac{1}{6} \text{ h}$

2. Find the unit rate

$\begin{array}{rcl}\text{unit rate} & = & \dfrac{\text{miles}}{\text{hours}}\\\\& = & \dfrac{\frac{3}{4}\text{ mi}}{\frac{1}{6}\text{ h}}\\\\& = &\dfrac{3}{4} \times \dfrac{6}{1}\text{ mi/h}\\\\& = & \dfrac{3}{2} \times\text{3 mi/h}\\\\& = & \textbf{4.5 mi/h}\\\end{array}\\\text{The unit rate is $\large \boxed{\textbf{4.5 mi/h}}$}$