Let's call the 13¢ stamps a and the 18¢ stamps b:
a+b = 42 and therefore a= 42-b (formula 1)
0.13a+0.18b= 6.66 In this formula, substitute the value of a according to formula 1:
0.13(42-b)+0.18b= 6.66 Multiply on the left to get rid of the parenthesis:
5.46-0.13b+0.18b= 6.66 Subtract 5.46 from both sides:
-0.13b+0.18b= 1.20 Add on the left:
0.05b= 1.20 Divide both sides by 0.05
b= 24 You have 24 18¢ stamps and:
42-24= 18 13¢ stamps
Check: (24 x 0.18) + (18 x 0.13)= 6.66 Correct.
Answer:
B hope this helps :)
Step-by-step explanation:
Answer:
She can double the base length of the base so that the new volume is 120 cubic inches
Step-by-step explanation:
Answer:
10 units
Step-by-step explanation:
Allow me to revise your question for a better understanding.
<em>"In the xy-plane, the parabola with equation y = (x − 11) ² intersects the line with equation y = 25 at two points, A and B. What is the length of AB" </em>
Here is my answer
Because the parabola intersects the line with equation y = 25 Substituting y = 25 in the equation of the parabola y = (x - 11)², we get
25 = (x - 11)²
<=>x - 11 = ± 5
<=>
Thus A(16, 25) and B(6, 25) are the points of intersection of the given parabola and the given line.
So the length of AB = √[(16 - 6)² + (25 - 25)²]
= √100 = 10 units