Cross multiply to get 8k+24=56 then solve for k so subtract 24 from each side to get 8k=32 so k=4
Answer:
15.5 ft
Step-by-step explanation:
The geometry of the problem can be modeled by a right triangle with hypotenuse 16 ft and one side length of 4 ft. If x represents the height of the ladder on the building, then the Pythagorean theorem tells us ...
x^2 + (4 ft)^2 = (16 ft)^2
x^2 = 240 ft^2 . . . . . . subtract 16 ft^2
x ≈ 15.5 ft . . . . . . . . . . take the square root
The top of the ladder is about 15.5 ft above the ground.
Answer:
4π in ≈ 12.57 in
Step-by-step explanation:
One full revolution (2π radians) is made in 60 minutes. In 40 minutes, the hand moves through an angle θ of (40/60)(2π) = 4π/3 radians. The length of the arc is ...
s = rθ = (3 in)(4π/3) = 4π in ≈ 12.57 in
Let x = amount of 45% antifreezeLet y = amount of 70% antifreeze EQUATION 1: x + y = 150 (total of 150 gallons mixed) EQUATION 2: .45x + .75y = .55(x + y) Simplify and solve the system of equations Multiply second equation by 100 on both sides to remove the decimals 45x + 75y = 55(x + y) Combine like terms 45x + 75y = 55x + 55y 45x - 55x + 75y - 55y = 0 -10x + 20y = 0 Now we have the following system of equations: x + y = 150 -10x + 20y = 0 Multiply the first equation by -10 to get opposite coefficients for x; add the equations to eliminate x 10x + 10y = 1500 -10x + 20y = 0 ------------------------------ 30y = 1500 Solve for y 30y = 1500 y = 50 Since the total mixed gallons is 150, x = 150 - 50 = 100 So we need 100 gallons of the 45% antifreeze and 50 gallons of the 70% antifreeze
