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4 years ago

One number is eight less than the second number. Twice the first is 9 more than 3 times the second. Find the numbers

Mathematics

1 answer:

Alik [6]4 years ago

7 0

Answer:

-49/3 and -25/3

Step-by-step explanation:

Let the numbers be represented by f and s (first and second). Then f = s - 8. Also, 2f = 3s + 9. Solve this system for f and s:

Substituting s - 8 for f in the 2nd equation, above, yields

2(s - 8) = 3s + 9, or 2s - 16 = 3s + 9. Then 3s = -25, and s = -25/3. The first number is then f = s - 8, or f = -25/3 - 8, or f = -49/3.

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10. The sum of two numbers is 6 less than twice the first number. Their difference is 10 less than four times the second number.

Ilya [14]

Answer:

10 and 4.

Step-by-step explanation:

Let x be the first number.

Let y be the second number.

x + y = 2x - 6

x - y = 4y - 10

x = 4y - 10 + y

x = 5y - 10

(5y - 10) + y = 2(5y - 10) - 6

6y - 10 = 10y - 20 - 6

6y - 10 = 10y - 26

6y - 10y = -26 + 10

-4y = -16

y = 4

x - (4) = 4(4) - 10

x - 4 = 16 - 10

x - 4 = 6

x = 6 + 4

x = 10

3 0

4 years ago

Guys please help out with this asap ! thanks

yKpoI14uk [10]

You’re gonna wanna round up both sides of your equation which will give u 224, then divide both by 16 which will leave u with 178

7 0

3 years ago

Which of the following graphs shows the solution set for the inequality below? 3|x + 1| < 9

Bas_tet [7]

Step-by-step explanation:

The absolute value function is a well known piecewise function (a function defined by multiple subfunctions) that is described mathematically as

$f(x) \ = \ |x| \ = \ \left\{\left\begin{array}{ccc}x, \ \text{if} \ x \ \geq \ 0 \\ \\ -x, \ \text{if} \ x \ < \ 0\end{array}\right\}$ .

This definition of the absolute function can be explained geometrically to be similar to the straight line $\textbf{\textit{y}} \ = \ \textbf{\textit{x}}$ , however, when the value of x is negative, the range of the function remains positive. In other words, the segment of the line $\textbf{\textit{y}} \ = \ \textbf{\textit{x}}$ where $\textbf{\textit{x}} \ < \ 0$ (shown as the orange dotted line), the segment of the line is reflected across the x-axis.

First, we simplify the expression.

$3\left|x \ + \ 1 \right| \ < \ 9 \\ \\ \\\-\hspace{0.2cm} \left|x \ + \ 1 \right| \ < \ 3$ .

We, now, can simply visualise the straight line, $y \ = \ x \ + \ 1$ , as a line having its y-intercept at the point $(0, \ 1)$ and its x-intercept at the point $(-1, \ 0)$ . Then, imagine that the segment of the line where $x \ < \ 0$ to be reflected along the x-axis, and you get the graph of the absolute function $y \ = \ \left|x \ + \ 1 \right|$ .

Consider the inequality

$\left|x \ + \ 1 \right| \ < \ 3$ ,

this statement can actually be conceptualise as the question

$``\text{For what \textbf{values of \textit{x}} will the absolute function \textbf{be less than 3}}"$ .

Algebraically, we can solve this inequality by breaking the function into two different subfunctions (according to the definition above).

Case 1 (when $x \ \geq \ 0$ )

$x \ + \ 1 \ < \ 3 \\ \\ \\ \-\hspace{0.9cm} x \ < \ 3 \ - \ 1 \\ \\ \\ \-\hspace{0.9cm} x \ < \ 2$

Case 2 (when $x \ < \ 0$ )

$-(x \ + \ 1) \ < \ 3 \\ \\ \\ \-\hspace{0.15cm} -x \ - \ 1 \ < \ 3 \\ \\ \\ \-\hspace{1cm} -x \ < \ 3 \ + \ 1 \\ \\ \\ \-\hspace{1cm} -x \ < \ 4 \\ \\ \\ \-\hspace{1.5cm} x \ > \ -4$

*remember to flip the inequality sign when multiplying or dividing by

negative numbers on both sides of the statement.

Therefore, the values of x that satisfy this inequality lie within the interval

$-4 \ < \ x \ < \ 2$ .

Similarly, on the real number line, the interval is shown below.

The use of open circles (as in the graph) indicates that the interval highlighted on the number line does not include its boundary value (-4 and 2) since the inequality is expressed as "less than", but not "less than or equal to". Contrastingly, close circles (circles that are coloured) show the inclusivity of the boundary values of the inequality.