Answer:
Cost of one pencil: 
Cost of one eraser: 
Step-by-step explanation:
Let be "p" the cost in dollars of one pencil and "e" the cost in dollars of one eraser.
Based on the information given in the exercise, you can set up the following system of equations:

You can use the Elimination Method to solve the system of equations.
Multiply the first equation by -3 ad the second one by 4. Then add the equations and solve for "e":
{
Substitute the value of "e" into any original equation and solve for "p":

As the three longitudinal lines are parallel:
angle 4 = 5 = 6 = 82 degree (corresponding angles) = 9 = 8 = 7 = 82 degrees (vertical angles)
and
angle 11 = 180-82= 98 degrees (linear pair)
so:
angle 10 = 11 = 12 = 98 degrees (corresponding angles) = 3 = 2 = 1 = 98 degrees (vertical angles)
.
hope you got it
The vertex to this quadratic equation is 2
Answer:
16/45
Step-by-step explanation:
Step 1: When dividing fractions, use “KFC”. It means Keep the first fraction, Flip the second one, and
Change it to multiplication
-4/20 ÷ -9/16 → -4/20 ∙ 16/-9
Step 2: Reduce any fractions if necessary, it makes multiplying them easier and you will have to reduce anyway at the end. It’s easier arithmetic to reduce at this step. The first fraction reduces because both the numerator and denominator are divisible by 4.
-1/5 ∙ 16/-9
Step 3: Multiply numerators and denominators together to get one fraction
(-16)/(-45)
Step 4: Cancel out the negatives, a negative divided by a negative is a positive. Our final answer is
16/45