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If the lines /1 and /2 are parallel, what must be value of y?

If the lines /1 and /2 are parallel, what must be value of y?-example-1
User Nndru
by
3.1k points

1 Answer

10 votes
10 votes

ANSWER

y = 130 degrees

Explanation

Key points to note in the provided figure

Alternate exterior angles are equal

The sum of supplementary angles is 180 degrees

From the figure given, angle y and angle 5x are alternate exterior angles

Since alternate exterior angles are equal. Hence, angle y = angle 5x

y = 5x

Also, angle (2x - 2) and y are supplementary angles

Recall, the sum of supplementary angles is 180 degrees

Hence, we have

y + (2x - 2) = 180

Note, y = 5x

substitute y = 5x into the above equation

5x + (2x - 2) = 180

Open the parenthesis

5x + 2x - 2 = 180

Collect the like terms

5x + 2x - 2 = 180

7x - 2 = 180

Add 2 to both sides of the equation

7x - 2 + 2 = 180 + 2

7x = 182

Divide both sides by 7

7x/7 = 182/7

x = 26 degrees

Since we have gotten the value of x = 26 degrees. Hence, we can now find the value of y

Recall, y = 5x

y = 5(26)

y = 130 degrees

User Niklas Schnelle
by
2.8k points