One pound of grapes costs $1.55. Which equation correctly shows a pair of equivalent ratios that can be used to find the cost of 3.5 pounds of grapes?
StartFraction 1.55 over 1 EndFraction = StartFraction x over 3.5 EndFraction
StartFraction 1.55 over 1 EndFraction = StartFraction 3.5 over x EndFraction
StartFraction 1 over 1.55 EndFraction = StartFraction x over 3.5 EndFraction
StartFraction x over 1.55 EndFraction = StartFraction 1 over 3.5 EndFraction

StartFraction 1.55 over 1 EndFraction = StartFraction 3.5 over x EndFraction

Step-by-step explanation:

1 = 1.55

x = 3.5

1.55/1 =3.5/x

1.55/1 = 3.5/x correctly shows the equivalent ratios

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

the answer is b