Question

What is the value for y? ​

Answer 1

y= 14

Explanation:

Given that AC= BC, △ABC is an isosceles triangle.

∠CBA= ∠CAB (base ∠s of isos. △)

∠CBA= 50°

∠ACB +50° +50°= 180° (∠ sum of △ABC)

∠ACB +100°= 180°

∠ACB= 180° -100°

∠ACB= 80°

Given that ∠ACB= (5y +10)°,

(5y +10)°= 80°

5y +10= 80

5y= 80 -10 (-10 on both sides)

5y= 70 (simplify)

y= 70 ÷5 (÷5 throughout)

y= 14