Question

The value of y is:

please help thanks so much.

Answer 1

• C) 14

Explanation:

Parallel lines divide the transversals proportionally.

Set proportions and solve for y:

• y/(y + 21) = 10/(10 + 15)
• y / (y + 21) = 10/25
• y / (y + 21) = 2/5
• 5y = 2(y + 21)
• 5y = 2y + 42
• 5y - 2y = 42
• 3y = 42
• y = 14

Correct choice is C

Answer 2

y = 14

Explanation:

If a line is parallel to a side of a triangle and it intersects the other two sides then it divides those sides proportionally , that is

`(y)/(21)` =
`(10)/(15)` =
`(2)/(3)` ( cross- multiply )

3y = 42 ( divide both sides by 3 )

y = 14