Question

Please help mathematics worksheet​

Answer 1

Explanation:

a)2/5a=4/a-1

By cross multiplication:

5a×4=2(a-1)

20a=2a-2

20a-2a=-2

18a=-2

a=-2/18

a=-1/9

b)7/2d-5=9/3d+4

By cross multiplication:

7(3d+4)=9(2d-5)

21d+28=18d-45

21d-18d=-45-28

3d=-73

d=-73/3

c)3/e+1 + 1/2e+1=0

3/e+1=-1/2e+1

By cross multiplication

3(2e+1)=-1(e+1)

6e+3=-e-1

6e+e=-1-3

7e=-4

e=-4/7

d)5/2f-5-4/7f+1=0

By cross multiplication

5/2f-5=4/7f+1

5(7f+1)=4(2f-5)

35f+5=8f-20

35f-8f=-20-5

27f=-25

f=-25/27

Answer 2

(a).

`(2)/(5a) = (4)/(a - 1) \\ \\ 20a = 2a - 2 \\ 18a =- 2 \\ a = - (1)/(9)`

(b).

`(7)/(2d - 5) = (9)/(3d + 4) \\ \\ 7(3d + 4) = 9(2d - 5) \\ 21d + 28 = 18d - 45 \\ 3d = - 73 \\ d = - (73)/(3)`

(c).

`(3)/(e + 1) + (1)/(2e + 1) = 0 \\ 3(2e + 1) = - (e + 1) \\ 6e + 3 = -(e + 1) \\ 7e = - 4 \\ e = - (4)/(7)`

(d).

`(5)/(2f - 5) - (4)/(7f + 1) = 0 \\ \\ (5)/(2f - 5) = (4)/(7f + 1) \\ \\ 5(7f + 1) = 4(2f - 5) \\ 35f + 5 = 8f - 20 \\ 27f = - 25 \\ f = - (25)/(27)`

(d).