Question

Question no 5 find the value of x and y

Answer 1

`(i)\ \ 18^o+3x-5+x+7=180^o\ \ \ \ \mathrm{[Sum\ of\ angles\ in\ straight\ line\ is\ 180^o.]}\\\mathrm{or,\ }18^o+4x+2=180^o\\\mathrm{or,\ }4x=180^o-2^o-18^o\\\mathrm{or,\ }4x=160^o\\\mathrm{or,\ }x=40^o\\(ii)\ \ x+y=180^o\ \ \ \ [\mathrm{Sum\ of\ angles\ in\ straight\ line\ is\ 180^o.]}\\\mathrm{or,\ }40^o+y=180^o\\\mathrm{or,\ }y=140^o`

`\bold{The\ figure\ in\ the\ question\ is\ misleading\ because\ you\ may\ take}\\\bold{another\ straight\ line\ with}\ x,\ 3x-5\ \bold{and\ } 18^o\ \bold{to\ consideration.}\\\bold{As\ the\ result,\ you\ get\ }x=41.75^o`

Answer 2

x = 41.75 , y = 138.25

Explanation:

the 3 angles x, 18, 3x - 5 lie on a straight line and sum to 180° , then

x + 18 + 3x - 5 = 180

4x + 13 = 180 ( subtract 13 from both sides )

4x = 167 ( divide both sides by 4 )

x = 41.75

the 2 angles x and y lie on a straight line and sum to 180° , that is

x + y = 180 ← substitute x = 41.75

41.75 + y = 180 ( subtract 41.75 from both sides )

y = 138.25