Plzzz help me I am timed plz

What is the value of 7x-9y when x=1 and y=8?

julsineya [31]

It would be - 65

7 x 1 = 7
9 x 8 = 72

7 - 72 = - 65

hope this helps you

4 0

3 years ago

The prices of commodities X,Y,Z are respectively x, y, z, rupees per unit. Mr. A purchases 4 units of Z and sells 3 units of X a

liubo4ka [24]

Answer:

$(x,y,z)=(1477, 1464, 1437)$

Step-by-step explanation:

Consider the selling of the units positive earning and the purchasing of the units negative earning.

Mr. A purchases 4 units of Z and sells 3 units of X and 5 units of Y
Mr.A earns Rs6000

So, the equation would be

$3x + 5y - 4z = 6000$

Mr. B purchases 3 units of Y and sells 2 units of X and 1 units of Z
Mr B neither lose nor gain meaning he has made 0₹

hence,

$2x - 3y + z = 0$

Mr. C purchases 1 units of X and sells 4 units of Y and 6 units of Z
Mr.C earns 13000₹

therefore,

$- x + 4y + 6z = 13000$

Thus our system of equations is

$\begin{cases}3x + 5y - 4z = 6000\\2x - 3y + z = 0\\ - x + 4y + 6z = 13000\end{cases}$

<u>Solving </u><u>the </u><u>system </u><u>of </u><u>equations</u><u>:</u>

we will consider elimination method to solve the system of equations. To do so ,separate the equation in two parts which yields:

$\begin{cases}3x + 5y - 4z = 6000\\2x - 3y + z = 0\end{cases}\\\begin{cases}2x - 3y + z = 0\\ - x + 4y + 6z = 13000\end{cases}$

Now solve the equation accordingly:

$\implies\begin{cases}11x-7y=6000\\-13x+22y=13000\end{cases}$

Solving the equation for x and y yields:

$\implies\begin{cases}x= \dfrac{223000}{151}\\\\y= \dfrac{221000}{151}\end{cases}$

plug in the value of x and y into 2x - 3y + z = 0 and simplify to get z. hence,

$\implies z= \dfrac{217000}{151}$

Therefore,the prices of commodities X,Y,Z are respectively approximately 1477, 1464, 1437

6 0

2 years ago

Please help I’m having trouble with this question!

mezya [45]

ok thanks for letting me know you need help

4 0

3 years ago

Caleb has driven 820 miles of his road trip. He has 20% of his trip left to go. How many miles does he have left to go? Need asp

Neporo4naja [7]

He has 164 miles left

5 0

3 years ago

A bank loaned out $21,500 , part of it at the rate of 11% annual interest, and the rest at 10% annual interest. The total intere

Luda [366]

Answer:

The loaned amount at 11 % is $ 19,000

The loaned amount at 10 % is $ 2,500

Step-by-step explanation:

Given as :

The total loan amount = $21,500

The total interest earn = $2,340.00

The rate of interest are 11 % and 10 %

Let The loan amount at 11 % rate = $P

and The loan amount at 10 % rate = $21,500 - $P

Let The loan took for 1 year

Now,<u> From Simple Interest method </u>

Simple Interest = $\dfrac{\textrm Principal\times \textrm Rate\times \textrm Time}{100}$

$SI_1$ = $\dfrac{P_1\times R_1\times \textrm Time}{100}$

Or, $SI_1$ = $\dfrac{P\times 11\times \textrm 1}{100}$

Similarly

$SI_2$ = $\dfrac{21,500 - P\times 10\times \textrm 1}{100}$

∵ $SI_1$ + $SI_2$ = $2,340

Or, $\dfrac{P\times 11\times \textrm 1}{100}$ + $\dfrac{21,500 - P\times 10\times \textrm 1}{100}$ = $2,340

Or, 11 P - 10 P + 215000 = 234000

Or, P = 234000 - 215000

∴ P = $ 19,000

And $21,500 - $ 19,000 = $ 2,500

Hence The loaned amount at 11 % is $ 19,000

And The loaned amount at 10 % is $ 2,500 Answer

8 0

3 years ago