Answer:
tenths
Step-by-step explanation:
Suppose a number is given in the form ABC.ZYX
The place values would be:
C is ones
B is tens
A is hundreds
Z is tenths
Y is hundredths
X is thousandths
Looking at the number 502.78, we see that "7" is the first right place after decimal, which is same as "Z", which is tenths.
Hence 7's place value is tenths
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":
1) given x^4 + 95x^2 - 500
2) split in two factors with common factor term x^2: (x^2 + )(x^2 - )
3) find two numbers that add up 95 and their product is - 500:
=> 100*(-5) = - 500 and 100 - 5 = 95
=> (x^2 + 100)(x^2 - 5)
4) factor x^2 - 5 = (x + √5) (x - √5)
5) write the prime factors: (x^2 + 100) (x + √5) (x -√5)
6) find the solutions:
x^2 + 100 = 0 => not possible
x + √5 = 0 => x = - √5
x - √5 = 0 => x = √5
Answer: x = √5 and x = - √5
