Question

Prosze o pomoc w matmie daje naj, cale zadanie 2

Answer 1

Verified answer

Odpowiedź:

a) [tex]\frac{5}{6} =\frac{4+5}{x+6}\\[/tex]

5(x+6)=6*(4+5)

5x+30=6*9

5x+30=54

5x=54-30

5x=24

x=4,8

b)

[tex]\frac{x}{3} =\frac{x+5}{3+4}[/tex]

x(3+4)=3(x+5)

7x=3x+15

7x-3x=15

4x=15

x=3,75

c) [tex]\frac{6}{8} =\frac{x-6}{8+4}[/tex]

6*(8+4)=8*(x-6)

6*12=8x-48

72+48=8x

120=8x

x=15

d) [tex]\frac{15-x}{2y} =\frac{15}{2y+3y}[/tex]

(15-x)(2y+3y)=2y*15

(15-x)*5y=30y

75y-5xy=30y

-5xy=30y-75y

-5xy=-45y /:(-5y)

x=9

Answer 2

Odpowiedź:

Zadanie 2. Na rysunkach proste k i l są równoległe. Oblicz x.

Twierdzenie Talesa.

a)

5/6 = 4/x

5*x = 6*4

5x = 24 /:5

x = 24/5

x = 4 4/5

-------

b)

x/3 = 5/4

4*x = 3*5

4x = 15 /:4

x = 15/4

x = 3 3/4

-------

c)

6/8 = x/12

8*x = 6*12

8x = 72 /:8

x = 9

-------

d)

2y/3y = (15-x)/x

2/3 = (15-x)/x

2*x = 3*(15-x)

2x = 45-3x /+3x

5x = 45 /:5

x = 9

-------

e)

3/x = 5/12

5*x = 3*12

5x = 36 /:5

x = 7 1/5

-------

f)

y/3,5y = x/10 ⇒ y+2,5y=3,5y

1/3,5 = x/10

3,5*x = 1*10

3,5x = 10 /:3,5

x = 10 : 35/10

x = 10 *10/35

x = 10*2/7

x = 20/7

x = 2 6/7

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