Solve 9x-7y=-7 i don't know how to do it so could you show me step by step please

1 answer:

8 0

First of all, you need to know what a 'solution' is, so you'll know it
when you see it.

A 'solution' to an equation is a number, or a set of numbers, that
you can write in place of the variables (the letters), and when you
do that, the equation will have only numbers in it, and it'll be a true
statement.

Your equation has two variables in it ... 'x' and 'y' . In order to find
just a single set of numbers for what both of them must be, you
would need two equations.

The way it stands now, with only one equation, there are actually
an infinite number of solutions. Each solution is a pair of numbers ...
one for 'x' and one for 'y' ... and if you write them into the equation
in place of 'x' and 'y', then the equation is a true statement.
I'll show you how to tell if a pair of numbers is a solution or not.

Here's what that looks like:

Say I give you two pairs of numbers, and I tell you that both of them
are solutions to your equation. The 'solutions' I give you are

          x=0
          y=1
and
          x=2
          y=3 .

You don't trust me, and you say to me "Wait just a minute there, dude !
Not so fast. I'll need to check them out and see if those are really solutions
to my equation."

You take the first pair and write it into your equation:
x=1, y=0
           9x - 7y = -7
                    9(0) - 7(1) = -7
                     0    - 7   = -7
                           -7   = -7
OK. That's a true statement.
So x=0, y=1 is a solution.

Now check the other one I gave you:
x=2, y=3
                   9x - 7y = -7
                    9(2) - 7(3) = -7
                       18 - 21 = -7
                          -3    = -7
This is NOT a true statement.
So x=2, y=3 is NOT a solution to your equation.
I pulled a fast one on you. If I was charging you money for solutions,
then you would not pay me for this one, because it's not a solution.

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Answer:

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b) 22 kcal come from fat.

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Diana invested $3000 in a savings account for 3 years. She earned $450 in interest over that time period. What interest rate did

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$\bf \qquad \textit{Simple Interest Earned}\\\\
I = Prt\qquad 
\begin{cases}
I=\textit{interest earned}\to &\$450\\
P=\textit{original amount deposited}\to& \$3000\\
r=rate\to r\%\to \frac{r}{100}\\
t=years\to &3
\end{cases}
\\\\\\
450=3000\cdot r\cdot 3\implies \cfrac{450}{3\cdot 3000}=r\implies \cfrac{1}{20}=r
\\\\\\
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Read 2 more answers

Help solving this math question

olga_2 [115]

22. B) $65,000,000 per year.

23. B) Education.

Step-by-step explanation:

Step 1; To find the average rate of change in annual budget between the two given years. We divide the difference in values for the two years by the period in between the two years. In 2008, the budget was $358,708,000 while in 2010 it was $488,106,000. The period in between was 2 years i.e 2009 and 2010.

The average rate of change = $\frac{488,106,000-358,708,000}{2}$ = $\frac{129,398,000}{2}$ = $64,699,000 per year.

So the average rate of change was $64,699,000 which approximately equals option B. $65,000,000.

Step 2; To find the human resources program's 2007 to 2010 ratio we divide the value in 2007 to the value in 2010. To find the other similar ratio, we divide the value in 2007 to the value in 2010 for all the other programs and determine which is closest to the human resources program.

Human resources program ratio = $\frac{4,051,050}{5,921,379}$ = 0.6841,