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":

Answer:
6 cm^2
Step-by-step explanation:
Area of Rectangle is L*W
L=3 and W=2
3*2=6
Answer:
2.7 x 5.2 = 14.04
Step-by-step explanation:
Answer:
-0.5 is not a solution
2 is a solution
Step-by-step explanation:
To check if something is a solution of the equation, you need to substitute the value in place of the variable
15 + 2y = -12 - 4y
15 + 2(-0.5) = -12 - 4(-0.5)
15 - 1 = -12 + 2
14 ≠ -10 ∴ -0.5 is not a solution
5 - 2(3x + 5) = 3 - 10x
5 - 2[3(2) + 5] = 3 - 10(2)
5 - 2(6 + 5) = 3 - 10(2)
5 - 12 - 10 = 3 - 120
-17 = -17 ∴ 2 is a solution