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g100num [7]
2 years ago
10

X + y = 21 3x – 2y = -12

Mathematics
2 answers:
kondaur [170]2 years ago
8 0

Answer:

x = 6 y = 15

Step-by-step explanation:

If this is simultaneous equations

x+y=21

3x-2y= -12

-3(x+y=21)

1(3x-2y= -12)

-3x -3y= -63

3x-2y= -12

-5y= -75

y= -75/-5

y= 15

x+y=21

x+15=21

x=21-15

x=6

Varvara68 [4.7K]2 years ago
7 0
This is the answer !!!!!!!!!!!

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victor are 60 de lei si merge la florarie pentru a-i cumpara mamei sale un buchet de flori. daca ar cumpara 9 garoafe si 4 trand
Alja [10]

Answer:

Număr de trandafiri = x = 5 trandafiri

Numărul este garoafe = y = 8 garoafe

Step-by-step explanation:

Pasul 1

Să reprezentăm:

Costul garoafelor = c

Costul trandafirilor = r

Victor are 60 de lei și merge la florărie să-i cumpere mamei sale un buchet de flori.

Dacă ar cumpăra 9 garoafe și 4 trandafiri, ar plăti 47 de lei.

Prin urmare,

9c + 4r = 47 ..... Ecuația 1

Dacă ar cumpăra doar trandafiri, toți banii ar fi suficienți pentru 12 bucăți.

Prin urmare,

12 trandafiri = 60 lei

1 trandafir = r lei

Cross Multiply

12r = 60 lei

r = 60 lei / 12

r = 5 lei

1 trandafir costă 5 lei

Înlocuim 5 cu r în ecuația 1

9c + 4 × 5 = 47

9c + 20 = 47

Colectează ca termeni

9c = 47 - 20

9c = 27

c = 27/9

c = 3 lei

Costul unei garoafe este de 3 lei

Pasul 2

Dar cumpără 13 flori (garoafe și trandafiri) și rămâne cu 5 lei rămași,

60 lei - 5 lei = 55 lei

Asta înseamnă că a cheltuit 55 de lei pe 13 flori.

Lasă

Număr de trandafiri = x

Numărul este garoafe = y

x + y = 13 ......... Ecuația 1

x = 13 - y

Din moment ce, Costul unei garoafe = 3 lei și 1 trandafir = 5 lei

3x + 5y = 55 ...... Ecuația 2

Înlocuim 13 - y cu x în ecuația 2

3x + 5y = 55

3 (13 - y) + 5y = 55

39 - 3y + 5y = 55

Colectează ca termeni

- 3y + 5y = 55 - 39

2y = 16

y = 16/2

y = 8

Rezolvarea pentru x

x = 13 - y

x = 13 - 8

x = 5

Prin urmare:

Număr de trandafiri = x = 5 trandafiri

Numărul este garoafe = y = 8 garoafe

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3 years ago
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gladu [14]
18sqrt(x)
I'm assuming that 3(sqrt(x))5 is equal to 15sqrt(x). If that is the case, just perform the multiplication within each term and treat the sqrt(x) as a variable when you add the all together. It is okay because they are like terms.

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HELP ASAP!!!!!!!! 15 POINTS + BRAINLIEST!!!!!!
Andre45 [30]
A) c=18
0.5c^2 +13=94
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0.5c^2 = 81
Square root of both sides to get c alone
0.5c=9
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c=18

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(x-2)^2+1=37
Subtract one from each side
(x-2)^2=36
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Write the equation in slope-intercept form y+3=4(x−1) plz do step by step
Rainbow [258]

Answer:y=4x -7

Step-by-step explanation:

The slope intercept form is: y= mx + b

Y+3 = 4(x-1) step one distribute 4

Y+3= 4x - 4 step two subtract 3 from both sides

Y=4x -7

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