If 140 g of silk yarn is required to weave 4 sq. m. of cloth, how much silk yarn is
required to weave 25 sq. m. of cloth?
How much cloth can be woven from
21 kg of silk yarn?

875g

600sqm

Step-by-step explanation:

140g/4 = 35g

1 sqm =35g

25sqm*35g=875g

1sqm=35g

21000/35=600

600sqm

345

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15