Scale Factor Basics
What is the scale factor if a shape doubles in size?
2
If a figure is enlarged using a scale factor of 2, how do the side lengths change?
They double
Write an algebraic expression for "5 more than a number x."
x + 5
Simplify: 3x+2x
5x
A rectangle has a length of 6 cm. After being enlarged by a scale factor of 2, what is the new length?
12 cm
If the original shape is 3 cm wide and the scaled version is 9 cm wide, what is the scale factor?
3
If a rectangle has dimensions of 5 cm by 8 cm and is enlarged by a scale factor of 4, what are the new dimensions?
20 cm by 32 cm
Translate "3 times a number decreased by 4" into an algebraic expression.
3x - 4
Simplify: 4x+7−2x−3
2x + 4
200: Jake has 3 times as many marbles as Sam. If Sam has x marbles, write an expression to represent how many marbles Jake has.
3x
A triangle has a height of 10 cm. If the scale factor is 0.5, what is the height of the new triangle?
5
A square has an area of 25 cm². If it is reduced by a scale factor of ½, what is the new area?
6.25 cm²
x+5=12.
x=7
Simplify: 5(2x+3)
10x + 15
A parking lot charges $5 for the first hour and $3 for each additional hour. Write an equation for the total cost (C) after h hours.
C=5+3h
A rectangle is reduced by a scale factor of ⅓. If the original width is 9 cm, what is the new width?
3 cm
A circle has a radius of 7 cm. If the scale factor is 3, what is the new radius?
21 cm
Solve for x: 3x=15
x=5
2(x+4)+3(x−1)
5x + 5
A baker needs three times as much flour as sugar for a recipe. If he has 8 cups of sugar, how much flour does he need?
24 cups
The perimeter of a rectangle is 24 cm. If a new shape is an enlargement with a scale factor of 3, what is its perimeter?
72 cm
A model car is built at a 1:10 scale. If the real car is 4 meters long, how long is the model?
0.4 meters
5(x−3)=20
x=7
3(2x−4)−2(3x+5)+7
-15
A store is offering a 25% discount on a jacket that costs $80. Write and solve an equation to find the final price.
x=80−0.25(80)=80−20=60, so $60