98 points! identify the variables and write out the system of inequalities

X = one pound packages of Value brand.

Y = one pound packages of Superior brand.

75 pounds x 16 ounces per pound = 1200 ounces.

120 pounds x 16 ounces per pound = 1920 ounces.

Value Blend  = 4 ounces of A and 12 ounces of B

Superior blend  = 8 ounces of A and 8 ounces of B

Grade A = 4x + 8y = 1200 ounces

Grade B = 12x + 8y = 1920 ounces

Solve for X in Grade A equation:

4x + 8y = 1200

Subtract 8y from each side:

4x = 1200-8y

divide all terms by 4:

x = 300 - 2y

Replace X in the 2nd equation with the X above:

12(300-2y) + 8y = 1920

Distribute:

3600 - 24y + 8y = 1920

Combine Y terms:

3600-16y = 1920

Subtract 3600 from each side:

-16y = -1680

Divide both sides by -16:

y = -1680 / -16

y = 105

Replace y with 105 in the last X equation:

x = -2y +300

x = -2(105) + 300

x = -210 + 300

x = 90

90 one pound packages of Value brand

105 one pound packages of Superior brand

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: