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Firlakuza [10]
3 years ago
15

I'd really appreciate some help on these questions, I'm really struggling

Mathematics
1 answer:
nikklg [1K]3 years ago
6 0
We can use linear combinations of the equations to eliminate variables.

3x - 4y = 1
-2x + 3y = 1

To eliminate y we'll make the linear combination of 3 times the first equation minus four times the second. 

9x - 12y = 3
-8x + 12y = 4

Adding,
x = 7

We could solve for y directly but let's use another linear combination, twice the first plus three times the second:

2(3x - 4y) + 3(-2x + 3y)= 2(1)+3(1)

y = 5

Check: 3(7)-4(5)=1 good.   -2(7)+3(5)=1 good.

Q18 Answer: (7,5)

y = -3x + 5
5x - 4y = -3

4y +1(5x - 4y) = 4(-3x + 5) + 1(-3)

5x = -12x + 20 -3

17 x = 17

x = 1
y = -3(1) + 5 = 2
Check: 5(1) - 4(2) = -3 good

Q19 Answer (1,2)

6x + 5y = 25
x = 2y + 24
6x = 12y + 144
5y = 25 - 12y - 144
17y = -119
y = -119/17= -7
x = 2y+24= 10
Check: 6(10)+5(-7)=25 good   2y+24=2(-7)+24=10=x good

Q20 Answer (10,-7)


3x + y = 18
-7x + 3y = -10
9x  + 3y = 54
9x - -7x = 54 - -10
16x = 64
x=4
y = 18 -3x = 18-12=6

Check: 3(4)+6=18 good,  -7(4)+3(6)=-10 good

Q21 Answer: (4,6)

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Need help,please. Just need to know how to find N
Iteru [2.4K]

Answer:

16

Step-by-step explanation:

because 7 times 4 is 28

4 times 4 is 16.

also it says 1/4 and yeah the little box is 1/4 of the big one so that is your answer  <3 :]

4 0
3 years ago
Gianni was thinking about paying his mother back in less than 100 weeks if he pays his mother $20 a week how many week will it t
weeeeeb [17]
What is the total amount of money he owes back?
6 0
3 years ago
Read 2 more answers
Find the missing length indicated<br><br> Thank you!
Novay_Z [31]

Answer:

C

Step-by-step explanation:

The big triangle and small triangles are similar so their corresponding sides are in proportion.

x/15 = 15/9

x= 15*15/9

x=25

6 0
2 years ago
A basket of the fruit contains 12 apples, 8 bananas, and 6 oranges. What is the ratio of bananas to apples? (Please simplify)
mrs_skeptik [129]

Answer:

2 : 3

Step-by-step explanation:

bananas to apples = 8 : 12

simplify by dividing both values by highest common factor of 4:

8 ÷ 4 : 12 ÷ 4 = 2 : 3

6 0
2 years ago
The cake recepi calls for 3 cups of sugar to every 2 cups of flour. if i use 9 cups of sugar how many cups of flour will i need?
scZoUnD [109]

Answer: 6cups of flour

Step-by-step explanation:

3cups of sugar to 2cups of flour

9cups of sugar to xcups of flour

Let sugar rep s

Flour rep f

So we have;

3s=2f

9s= xf

Cross multiply

3s×xf=2f×9s

Xf=2f×9s/3s

Xf=6f

Therefore, 9cups of sugar will be to 6cups of flour

7 0
3 years ago
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