Writing Equations
I spent $20 at the store. I bought $15 worth of candy. I spent some money on gum (g). Write an addition equation to represent the situation.
15 + g = 20
Solve:
b - 7 = 11
b = 18
Is 4 a solution to the equation:
2c = 14
Explain why or why not.
No. Four is not a solution. If you substitute 4 in for c, 2 x 4 = 8.
8 is not equal to 14. It is not a solution.
What do these symbols represent?
< and >?
< represents "less than"
> represents "greater than"
What sign can represent "at most"?
"less than or equal to"
Cameron spends $30 on ice cream. He buys pints for $4 each. He also buys a gallon of ice cream for $6. Write an addition equation to represent the situation. Use "p" for pints.
4p + 6 = 30
Solve:
10 + g = 32
What is a solution?
A solution is like an answer to an equation. It is a value that makes the statement (equation, inequality) TRUE.
Write the inequality:
Three added to n is less than 14
3 + n < 14
What's the inverse of subtraction?
What's the inverse of division?
The inverse of subtraction is addition.
The inverse of division is multiplication.
I earned some cash babysitting. I took that money and I bought a new shirt for $14.50. When I was done shopping, I had $28.50 left. Write a subtraction equation to represent the situation and to find how much I earned, e, babysitting.
e - 14.50 = 28.50
Solve:
5 1/2 = b - 12 1/4
b = 17 3/4
Which of the values is a solution to 2k + 3 = 11
k= 3
k = 4
k =5
k = 4 is a solution.
Write the inequality:
Four times k is greater than 45
4k > 45
The Division Property of Equality tells me...?
You can divide to both sides of an equation and the equation will stay the same.
On Saturday and Sunday, Mike went running and burned a total of 647. 5 calories. He burned 320 of them on Saturday. Write an addition equation that could be used to find the number of calories burned on Sunday.
320 + s = 647.5
s represents the number of calories burned on Sunday.
Solve:
d/3 = 14
(d divided by 3 equals 14)
d = 42
d - 8.4 = 8.6
Which is a solution?
15, 16, 17
17 is a solution.
If you graph the inequality, d < 13, which direction would the arrow go? Explain why your answer is correct.
The arrow would go to the left. It would go to the left so anything less than 13 would be included.
x > 1/3
What type of dot would be graphed for this inequality and what direction would the arrow/line go in?
It would be an open dot and the arrow would go to the right.
Together, Annie and Jenny saved $365.50. If Annie saved $215 of that, how much did Jenny save? Create an addition equation that could be used to find how much money "m" that Jenny saved.
215 + m = 365.50
1.75d = 12.25
Solve for d.
d = 7
(2m + 2) + 4 = 16
Which of the following is a solution to the equation?
4, 5, 6, or 7?
5 is the solution.
Explain how you know if the dot in plotting an inequality on a number line is open or closed.
If the inequality is greater than or less than, the dot is open. If it is greater than or equal to or less than or equal to, the dot is closed.
Matt saved $200 to buy new hats for each of his teammates. Each hat costs $24.50. The inequality 200 ≥ 24.50h , represents the situation where h= how many hats he can buy. What's the greatest number of hats that Matt can buy? 9 hats, 8 hats, or 7 hats?
8 hats. If he buys 8 hats, he'll spend $196.