Solving Proportions . Lesson 2-7. Warm Up:
You are making beaded necklaces using a pattern in which 2 large red beads are followed by 3 small blue beads. Each set of 5 beads adds 1 ¼ inches to the length of the necklace. How many of each color bead will you need for a 20-in. necklace. Explain your answer.
A __________________ is an equation that states two ___________ are equal.
A. What is the solution to the proportion ?
___________________________ Write the equation
5●x = 7 ●4
5x = 28
x = 5.6
These examples are reviews of problems similar to ones you have solved in earlier grades.
3●3 = 5 ● y
5●x= 9 ● 15
9 = 5y
5y = 9
y = 1.8
In example B, the symmetric property was used to rewrite the problem with the variables on the left side of the equation.
In both example B and C, the first two steps could have been combined into one step.
Cross - multiply have solved in earlier grades.
6n = 5(2n + 4)
6n = 10n + 20
Simplify using the distributive property.
6n – 10n = 10n –10n + 20
“Move” the “10n” by subtracting it from both sides.
– 4n = 20
Divide each side by -4 so that only 1n remains.
n = -5
4 have solved in earlier grades. w = 2(w + 3)
4w = 2w + 6
Simplify using the distributive property
4w – 2w= 2w – 2w+ 6
Move “2w” by subtracting from each side.
Divide each side by 2 – the coefficient of w
Try each of the problems below. have solved in earlier grades.