Solve the inequality.

If y varies directly as x and y = 21 when x = 5, find x when y = 42.

Lorico [155]

Answer: 10

Step-by-step explanation:

varies directly means: $\frac{y}{x} = k$

Step 1: solve for k ⇒ $\frac{21}{5} = k$

Step 2: plug in the given value and k to solve for the missing value: $\frac{42}{x} = \frac{21}{5}$

42(5) = 21(x)

$\frac{42(5)}{21} = \frac{21(x)}{21}$

2(5) = x

10 = x

5 0

3 years ago

Please answer URGENT area of shapes THANKS !!!!!!!!!!!

Vinil7 [7]

Answer:

Hope 292.5 is right.

Step-by-step explanation:

First thing, multiply the triangles base and height which will give you 143 then divide it by two which is 71.5. Then to the parallelogram which is base times height which is 117. Moving on to the trapezoid, meanin one-hal times height times first base plus second base giving you 104. Finally, add'em up, giving you a total of 292.5.

4 0

3 years ago

How many years would it take for a person it the united states to eat 855 pound of apples?

Oxana [17]

Depends on many pounds of apples they eat a year. Take the number they eat a year and divide it by 855

4 0

3 years ago

Read 2 more answers

Can anyone help me with this Midterm Advanced Algebra problem. (DONT ANSWER IF YOUR NOT SURE)

tigry1 [53]

Answer:

y = -1/2x + 13/2

Step-by-step explanation:

The slope of a line that is perpendicular to a line will be a negative reciprocal. When you rewrite 2x-7=8 into slope-intercept form, you get y=2x-8. The negative reciprocal of the slope 2x is -1/2x. There is only one option with this slope. If you're still not sure then you can use a graphing calculator to check this. An online one would be desmos

3 0

3 years ago

Determine which of these sequences is an arithmetic sequence. Then determine the explicit formula that would be used to define t

vagabundo [1.1K]

6)

34, 43, 52, 61, ...

43-34 = 9; 52-43 = 9; 61-52 = 9

The difference between one term and the next is a constant so it is arithmetic sequence

first term: a = 34

difference: d = 9

so the formula:

$a_n=a+d(n-1)\\\\a_n=34+9(n-1)\\\\a_n = 34+9n-9\\\\\underline{a_n=9n+25}$

7)

10, 6, 2, -2, ...

6-10 = -4; 2-6 = -4; -2-2 = -4

The difference between one term and the next is a constant so it is arithmetic sequence

first term: a = 10

difference: d = -4

so the formula:

$a_n=a+d(n-1)\\\\a_n=10+(-4)(n-1)\\\\a_n = 10-4n+4\\\\\underline{a_n=-4n+14}$

8)

-3, -10, -17, -24, ...

-10-(-3) = -7; -17-(-10) = -7; -24-(-17) = -7

The difference between one term and the next is a constant so it is arithmetic sequence

first term: a = -3

difference: d = -7

so the formula:

$a_n=a+d(n-1)\\\\a_n=-3+(-7)(n-1)\\\\a_n =-3-4n+7\\\\\underline{a_n=-7n+4}$

9)

7, 8.5, 10, 11.5, ...

8.5-7 = 1.5; 10-8.5 = 1.5; 11.5-10 = 1.5

The difference between one term and the next is a constant so it is arithmetic sequence

first term: a = 7

difference: d = 1.5

so the formula:

$a_n=a+d(n-1)\\\\a_n=7+1.5(n-1)\\\\a_n =7+1.5n-1.5\\\\\underline{a_n=1.5n+5.5}$

10)

30, 22¹/₂, 15, 7¹/₂, ...

22¹/₂-30 = -7¹/₂; 15-22¹/₂ = -7¹/₂; 7¹/₂-15 = -7¹/₂

The difference between one term and the next is a constant so it is arithmetic sequence

first term: a = 30

difference: d = -7¹/₂

so the formula:

$a_n=a+d(n-1)\\\\a_n=30+(-7\frac12)(n-1)\\\\a_n =30-7\frac12n+7\frac12\\\\ \underline{a_n=-7\frac12n+37\frac12}$

6 0

3 years ago