2y+18=42
2y=24
y=12
Hope this helps!
Answer:
You stopped at 2y-4=12
If we add same number to both sides the equation will remain true. For example if we have 5=5, and we add 7 to both sides, we get 12=12 which is also true. Now let's do this with our equation. Add 4 to both sides(to have only y on the left side). We get 2y=16, hence y=8.
Answer. 2y=16
Answer:
AB ║ CD. (Proved)
Step-by-step explanation:
See the attached diagram of the triangle.
It is given that Δ ACD is an isosceles triangle.
Therefore, AC = AD and ∠ ACD = ∠ ADC, ⇒ ∠ 3 = ∠ 4 .......... (1)
Again, given that ∠ 1 = ∠ 3 ........... (2)
Now, from equations (1) and (2) we can write, ∠ 1 = ∠ 4
Now, AB and CD are two straight lines and AD is the transverse line and hence, ∠ 1 and ∠ 4 are alternate angles that are equal.
Therefore, AB and CD are parallel straight lines and AB ║ CD. (Proved)
