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3 years ago

2x - 5y=-15 can someone walk me through this?

1 answer:

3 0

The equation given in the question has two unknown variables in the form of "x" and "y". The exact value of "x" and "y" cannot be determined as two equations are needed to get to the exact values of "x" and "y". This equation can definitely be used to show the way for determining the values of "x" in terms of "y"and the value of "y" in terms of "x". Now let us check the equation given.
2x - 5y = - 15
2x = 5y - 15
2x = 5(y - 3)
x = [5(y - 3)]/2
Similarly the way the value of y can be determined in terms of "x" can also be shown.
2x - 5y = - 15
-5y = - 2x - 15
-5y = -(2x + 15)
5y = 2x + 15
y = (2x +15)/5
= (2x/5) + (15/5)
= (2x/5) + 3
So the final value of x is [5(y -3)]/2 and the value of y is (2x/5) + 3.

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you have 3.75 to spend at a vending machine. You want to buy at least three health bars. Regualr health bars cost 0.75 each and

DedPeter [7]

Answer:

Let x be the number of regular health bars you buy and y the number of strawberry health bars you buy. Then:

0.75x+1.25y=3.75

x+y>=3

Step-by-step explanation:

For the first equation, we have to assume that you will spend all of your money, otherwise it becomes an inequation. The money you spend on regular bars is 0.75x dollars and the money you spend on strawberry bars is 1.25y, so if you spend your 3.75 dollars on the bars, then 0.75x+1.25y=3.75.

For the second, you will always buy x+y health bars, regular and strawberry. There isn't enough information to make this into a equation, the only thing we can deduce is the inequation x+y>=3.

If we also assume that x and y are integers (we can't buy half-bars or one-fourth of a bar) then the minimum number of bars we can buy is 3 (3 strawberry bars) and the maximum is 5 bars (5 regular bars). x+y must be an integer too, so the possibilities for the second equation are x+y=3, x+y=4 and x+y=5. There is a finite number of solutions in any case.

4 0

3 years ago

-3j - (-4) over -6 = 12 j= ?

babymother [125]

Answer:

j =76/3

Step-by-step explanation:

-3j - -4

------------------ = 12

-6

Multiply each side by -6 to clear the fraction

-3j +4

------------------ * -6 = 12 *-6

-6

-3j +4 = -72

Subtract 4 from each side

-3j +4-4 = -72 -4

-3j = -76

Divide each side by -3

-3j/-3 = -76/-3

j = 76/3

5 0

3 years ago

A line has a slope of 10 and includes the points (3, n) and (4,0). What is the value of n? n =

ExtremeBDS [4]

Answer:

The value of n = -10

Step-by-step explanation:

Given the points

(3, n)

(4,0)

Finding the slope between (3, n) and (4,0)

$\left(x_1,\:y_1\right)=\left(3,\:n\right),\:\left(x_2,\:y_2\right)=\left(4,\:0\right)$

As slope = 10

using the formula

Slope = [y₂ - y₁] / [x₂ - x₁]

so substituting the values

10 = [0 - n] / [4 - 3]

10 = -n / 1

10 = -n

n = -10

Therefore, the value of n = -10

8 0

2 years ago

Eight times a number plus five another number is -13. The sum of the two numbers is 1. What are the numbers?

Pani-rosa [81]

Eight *(a number) plus 5*(another number) is -13.

translates to:

8(x) + 5(y) = -13

The sum of (the number) and (the other number) is 1.

translates to:

(x) + (y) = 1

We have a system of two equations involving two unknowns: x and y.

$\rm 8x+5y=-13\\
~~x+~~y=~~~~1$

We can easily solve the system using Substitution or Elimination. Let's use Elimination this time.

We'll multiply the second equation by -8 so that the x's match up.

$\rm ~~~8x+5y=-13\\ -8x-8y=-8$

When we add the equations together, the x's will fall out of the equation, summing to zero. The 5y and -8y will sum to -3y and the right hand side will sum to -21.

$\rm -3y=-21$

Divide by -3,

$\rm y=7$

Plug back into one of your original equations to find the value of x,

$\rm x+y=1\\
x+7=1$

Subtract 7,

$\rm x=-6$

8 0

3 years ago

How is number 0.000063 written in scientific notation?

katen-ka-za [31]

Step-by-step explanation:

The scientific notation:

$a\times10^k$

1 ≤ a < 10 and k - any integer number

$0.000063=0\underbrace{.00006}_{5\to}3=6.3\times10^{-5}\\\\\\0.000063=6.3:100,000=6.3:10^5=6.3\times10^{-5}$

5 0

3 years ago