$680 is the answer...........
The sum of the measures of the angles of a triangle is 180 degrees.
Angles STU and STR are supplementary angles.
Angles R and STR are congruent.
m<STU + m<STR = 180
8x + m<STR = 180
m<STR = 180 - 8x
m<R = m<STR = 180 - 8x
m<RST + m<R + m<STR = 180
7x - 54 + 180 - 8x + 180 - 8x = 180
-9x + 360 = 180
-9x = -126
x = 14
The system:
y = 3 x - 7
15 x - 5 y = 14
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Using the substitution method:
15 x - 5 · ( 3 x - 7 ) = 14
15 x - 15 x + 35 = 14
0 · x = 14 - 35
0 · x = - 21
x , y ∈ ∅
Answer:
D ) There is no solution.
82.5 / 5.5 = 15
15 hrs.
i think that should be the answer but i didn't use the 2.3 -meter-thick clue...