Envision Math 2.0: Grade 7, Volume 2
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Envision Math 2.0: Grade 7, Volume 2 View details
4. Solve Problems Using Angle Relationships
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Exercise 10 Page 439

Use the fact that 125^(∘) and (5x+30)^(∘) are vertical angles.

x=19^(∘)

Practice makes perfect

Consider the given diagram

angles
We want to find the value of x. From the given diagram, we know that 125^(∘) and (5x+30)^(∘) are vertical angles. This means that both have the same measure. 125^(∘)=5x+30^(∘) Let's solve this equation for x. Note that to make calculations easier, we can ignore the symbol ^(∘) and add it to the result.
125=5x+30
Solve for x
125-30=5x+30-30
95=5x
95/5=5x/5
95/5=5x/5
95/5=x
19=x
x=19
We found that x=19^(∘).