23-11=12
She spent $12 on notebooks, and she bought six notebooks.
12/6=2
Each notebook costed $2.
Answer:
This question contains some errors; the correct question is:
You pack sandwiches for a mountain hike with your friends. Each sandwich takes 2 slices of bread, and each hiker eats one sandwich. How many slices of bread are used for n hikers? Write your answer as an expression.
The answer is:
(2n) slices of bread for n hikers
Step-by-step explanation:
According to the question, sandwiches packed for a mountain hike with friends is made of two (2) slices of bread.
Each hiker gets one sandwich
This, n hikers will get n× 1 sandwich
= (n) sandwiches.
If 1 sandwich contains 2 slices of bread, then (n) sandwiches for n hikers will contain:
(2 × n) slices of bread
That is, (2n) slices of bread.
The expression is (2n).
Solve for x over the real numbers:
x^2 - 4 x = 5
Subtract 5 from both sides:
x^2 - 4 x - 5 = 0
x = (4 ± sqrt((-4)^2 - 4 (-5)))/2 = (4 ± sqrt(16 + 20))/2 = (4 ± sqrt(36))/2:
x = (4 + sqrt(36))/2 or x = (4 - sqrt(36))/2
sqrt(36) = sqrt(4×9) = sqrt(2^2×3^2) = 2×3 = 6:
x = (4 + 6)/2 or x = (4 - 6)/2
(4 + 6)/2 = 10/2 = 5:
x = 5 or x = (4 - 6)/2
(4 - 6)/2 = -2/2 = -1:
Answer: x = 5 or x = -1
