Answer:
$52.44
Step-by-step explanation:
Long method:
1. Convert the percentage into a decimal (15/100 = 0.15)
2. Multiply the decimal by the cost of the haircut (0.15 x $45.60 = $6.84)
3. Add this product by the cost of the haircut ($6.84 + $45.60 = $52.44)
Quicker Way (easier w/ a calculator)
1. Add 100% to the percentage she wants to add (100% + 15% = 115%) You can also express this as a number (115/100 = 1.15)
2. Multiply this new percentage by the cost of the haircut (1.15 x $45.60 = 52.44)
In a single equation, it would be

1st blank: 2x
2nd blank: 4x
3rd blank: 8
4th blank: 16
5th blank: 4
4a + 6b = 10
2a - 4b = 12...multiply by -2
----------------
4a + 6b = 10
-4a + 8b = - 24 (result of multiplying by -2)
------------------add
14b = - 14
b = -14/14
b = -1
2a - 4b = 12
2a - 4(-1) = 12
2a + 4 = 12
2a = 12 - 4
2a = 8
a = 8/2
a = 4
so 12a = 12(4) = 48 <==
Answer:
-6/5
Step-by-step explanation:
Get y by itself to get the slope. So 18x+15y=90. Move 18x to the other side of the equation. Now you have 15y=-18x+90. Divide both sides by 15 to get y by itself. Now it's y= -18/15x + 6. Reduce -18/15 to the simplest fraction. You have y= -6/5x+6. Any number can replace the 6 in the equation to give you a parallel line...it's the slope that makes it parallel, not the y intercept. So y= -6/5x+10 or y=- -6/5x-1 would satisfy your parallel slope equation.