A side of the triangle below has been extended to form an exterior angle of 128°. Find the value of x.
1 answer:
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Answer:
x=1, y=7
Step-by-step explanation:
y = -3x + 10 - first equation
y=-3x + 4 - second equation
rearrange the expression to
-3x-y= -10
3x-y= -4
pick an equation and simplify; lets pick the second equation
3x-y= -4
divide 3 by both sides
x= - third equation
substitute the value of x into an equation; lets pick the first equation
-3x-y= -10
-3- y = -10
simplify. -3 cancels 3 so we are left with
-1(-4+y)-y = -10
simplify
4-y-y= -10
4-2y= -10
subtract 4 from both sides
-2y= -10-4
-2y= -14
divide -2 by both sides
y=7
substitute the value of y, (y=7) in an equation, we are using the second equation
3x-y= -4
3x-7= -4
3x = -4+7
3x= 3
divide 3 by both sides
x=1
so the answer is x=1, y=7