Answer:
Solution set= {(3,-9)}
Step-by-step explanation:
x² +6x-27=0
x² +9x-3x-27=0
x(x+9) -3(x+9)=0
(x-3)(x+9)=0
x-3=0; x+9=0
x=3; x=-9
Use this systems of equations to solve:
x = first antifreeze
y = second antifreeze
Isolate y.
x + y = 15
Subtract x from both sides.
y = -x + 15
Substitute y into the other equation.
.2x + .12(-x + 15) = .18(15)
Simplify.
.2x - .12x + 1.8 = 2.7
Subtract 1.8 from both sides.
.08x = .9
Divide both sides by .08
x = 11.25
Substitute x in the equation that we isolated y in.
y = -11.25 + 15
y = 3.75
11.25 L of the first antifreeze and 3.75 L of the second.
Answer:
6 hours.
Step-by-step explanation:
since the boat house charges 7 dollars we can subtract that from 43
43-7=36
since we have 36 left and the fee per hour is 6 we can devide
36÷6=6
Answer:B
Step-by-step explanation: