waecmaths question:
The value of three angles at a point are 3y - 45o, y + 25o and yo. Find the value of y
Option A:
40o
Option B:
68o
Option C:
76o
Option D:
58o
waecmaths solution:
$\begin{align} & 3y-{{45}^{\circ }}+y+{{25}^{\circ }}+{{y}^{\circ }}={{360}^{\circ }}\text{ }\!\!\{\!\!\text{ sum of }\angle \text{s at a point }\!\!\}\!\!\text{ } \\ & 5y-{{20}^{\circ }}={{360}^{\circ }} \\ & 5y={{380}^{\circ }} \\ & y=\frac{{{380}^{\circ }}}{5}={{76}^{\circ }} \\\end{align}$
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