-6b = -66
You divide -6 on both sides. A negative multiplied/divided by a negative equals a positive
-1 · -1 = 1
-1 ÷ -1 = 1
b = 11
22.5 (shower) = X (variable used in place of the amount of water she uses to wash clothes) - 7.5 (the amount she used in the shower is 7.5 gallons less than she uses for washing clothes)
22.5 = X - 7.5 《 This is the equation.
Solve is by adding 7.5 to both sides to cancel out the negative 7.5 and you get (X = 30).
If you simplify the expression you will get 18x - 15.
You can solve <span>9/x-4/y=8 for x or for y but NOT at the same time.
Solving for x: </span><span>9/x-4/y=8 Mult all 3 terms by xy to eliminate the fractions.
9(xy)/x - 4xy/y = 8xy => 9y - 4x = 8xy, or 9y = 4x + 8xy = 4x(1+2y)
then 9y = x [ 4(1+2y) ]
9y
therefore x = ------------
4(1+2y)
Solve for y using a similar approach.
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