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Kruka [31]
3 years ago
8

a teacher had 21 red pens. if the ratio of red pens to blue pens she owned was 3:1 , how many pens did she have in total

Mathematics
2 answers:
snow_lady [41]3 years ago
8 0
She had 21:7 because if you multiply 3:1 by 7 each it is 21:7 so she had 7 blue pens
erma4kov [3.2K]3 years ago
5 0
There are 21 red pens. For every 3 red pens, there is 1 blue pen.
Let's make these into a fraction equation.
21/p=3/1
p is the number of blue pens we have yet to find.
First, cross multiply.
21x1=21
px3=3p
Now, we have an equation of
21÷3p
We set it equal to 1, and we solve it.
21÷3p = 1
(21÷3p)×3p=1×3p
21=3p
21÷3=(3p)÷3
7=p
So, if there are 21 red pens, there are 7 blue pens.
We add these together to find the total number of pens the teacher has.
21+7=28
The teacher has 28 pens total.
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Answer:

the value of the smallest number is 3

Step-by-step explanation:

The computation of the value of the smaller number is shown below:

Given that

y = 4x + 2

y = 2x + 8

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4x + 2 = 2x + 8

4x - 2x = 8 - 2

2x = 6

x = 3

Hence, the value of the smallest number is 3

The same is to be considered

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dolphi86 [110]
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Jan bought 6 cookies and 4 doughnuts for 3.50. Tom bought 12 cookies and 5 doughnuts got 5.23. Write and solve a system of equat
iren2701 [21]
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x for how much one cookie costs and y for how much one doughnut costs
6x+4y=3.5
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solve by substitution: (elimination would work too)
4y=3.5-6x
y=0.875-1.5x
12x+5(0.875-1.5x)=5.23
12x+4.375x-7.5x=5.23
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now use x to solve for y:
6(0.19)+4y=3.5
1.14+4y=3.5
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4 0
3 years ago
Lesson 6 Practice Problems
inna [77]

Answer:

                               WHITE PAINT                                    PINK PAINT

                                       (CUPS)                                              (CUPS)

                                             4                                                         3        

                                            4/3                                                       1

                                            1                                                         3/4

                                            16/3                                                     4

                                             5                                                         15/4

-Lexi

6 0
3 years ago
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