Hello,
The line passes through (-1,3) and (9,11)
slope=(11-3)/(9+1)=8/10=4/5
y-3=4/5(x+1)
==>y=4/5 *x +19/5
Assuming that the cost per minute is the same for both months and the plan fee is the same, you can use y=mx+b for this
y is the cost of the phone plan, x is the cost per minute and b is the start cost.
so 19.41=25x+b for the first month
and 45.65=380x+b for the second month
solve both for b you get:
19.41-25x=b and 45.65-380x=b. from this we get
19.41-25x=45.65-380x
solve for x
328x=26.24 and x=0.08
this means the cost per minute is 0.08c/min (answer A)
rewrite the equation to calculate b, and where this time, the x is the number of minutes talked.
y=0.08x+b and plug in one of the two months
45.65=0.08 * 380 + b
Solve for b and b is 15.25
so the final equation is
y=0.08x+15.25 (answer B)
When the penny hits the ground, h will = 0.
So: Set h(t) = 0 = -4.9t^2 + 0t + 150 m
Then 4.9t^2 = 150, and so t^2 = sqrt(150 / 4.9) = plus or minus 5.53 sec.
We can use only the positive root, as we're measuring time.
t = 5.5 sec (answer)
Answer:
7 . 4 + 6 - 12 : 4 = 31
Step-by-step explanation:
* To solve this problem lets revise the order of operations in
mathematics
- The operations are:
# Addition
# Subtraction
# Multiplication
# Division
# Exponentiation
# Grouping ⇒ Parenthesis or brackets
- The order of these operations is:
# Parenthesis
# Exponents
# Multiplication and Division which comes first from left to right
# Addition and Subtraction which comes first from left to right
- There is a word made from the first letter of each operation
PEMDAS to remember the order of operations
* Lets solve the problem
∵ 7 . 4 + 6 - 12 : 4
∵ The (.) means multiply the numbers
∵ The symbol (:) means divided the numbers
∴ At first multiply 7 by 4 and divide 12 by 4
∴ (7 × 4) + 6 - (12 ÷ 4)
∴ 28 + 6 - 3
∵ Addition comes before subtraction from the left
∴ (28 + 6) - 3
∴ 34 - 3 = 31
∴ 7 . 4 + 6 - 12 : 4 = 31
I would assume it would be dividing both sides by three although if someone were to actually solve this I would say multiply 2 and 3 together first.
Hope this helps :)
