Show the steps and solution explanations.
a. x+4y=6
x+4y=15

b. x+4y=7
3x +12y=21

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

Step-by-step explanation:

x+4y=6

x+4y=15

x+4y=6

-(x+4y)=-15

x+4y=6

-x-4y=-15

0=-9

no solution

No Solution

x+4y=7

3x+12y=21

simplify 3x+12y=21 into x+4y=7

Infinitely many solutions

x-y=1

2x+y=4

x=y+1

2(y+1)+y=4

2y+2+y=4

3y=4-2

3y=2

y=2/3

x-2/3=1

x=1+2/3

x=3/3+2/3=5/3

x=5/3, y=2/3. (5/3, 2/3).

percentage - 25%

probability - 0.25

we know,

total amount of students in class = 20

total boys = 10

total girls = 10

no of girls who wear glasses = 10/2 = 5

probability of choosing a girl with glasses is =

number of girls wearing glasses/total number of students in the class = 5/20

thus, percentage of selecting a girl wearing glasses will be

= 5/20 × 100

= 5 × 5

25%

therefore,

probability will be 0.25

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