Using the expression 7x - 5, find the value when x is 3.
2 answers:
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Answer:
3 cm
Step-by-step explanation:
When we enlarge or shrink an object, we perform a dilation. A dilation preserves the relationship between sides and the exact angle measure. This means the original and the enlargement are proportional and any missing lengths can be found through a proportion.
A proportion is an equation where two ratios or fractions are equal. The ratios or fractions compare like quantities. For example, we will compare height over length of the original rectangle to an equal ratio of height to length of the enlargement. Since we do not know height of the enlargement, we will use a variable to write:
I can now cross-multiply by multiplying numerator and denominator from each ratio.
I now solve for h by dividing by 9.
The new height is 3 cm.
