Answer:
29
Step-by-step explanation:
Well "value" of 3x^2 - 7x + 9 when x = 4 is just x plugged into the expression
3 * 4^2 - 7 * 4 + 9
3 * 16 - 28 + 9
= 29
Answer:
150 mL
Step-by-step explanation:
We need a mixture that is at 50%, now we have 200 mL at 35% and another mixture that is at 70%, that is, we must calculate how much of this mixture is added, by the following equation
200 * 35% + x * 70% = 50% (x + 200)
70 + 0.7 * x = 0.5 * x + 100
0.7 * x - 0.5 * x = 100 - 70
0.2 * x = 30
x = 30 / 0.2
x = 150
150 mL must be added so that the mixture is 50%.
Answer:
Step-by-step explanation:
a) 20% decrease, b) 25% increase
$4.00/hat
4*3=12
18-12=6
6÷2=3
$3.00 is the price of one umbrella
