Answer:
a). x + y + 90° = 180°
b). x = 67°
y = 23°
Step-by-step explanation:
The sum of all angles in a triangle is 180°.
One of the angles in the figure is a right angle, or 90°. Therefore the sum of the three angles in the figure is:
x + y + 90 = 180
We are also told that x + 2 = 3y.
Rearranging that to isolate x gives us:
x = 3y - 2
Thake the first equation and substitute the above expression of in place of x:
x + y + 90° = 180°
(3y-2) + y + 90° = 180°
4y + 88° = 180°
4 y = 92°
y = 23°
To find angle x, use y = 23°
x = 3y - 2
x = 3*(23°) - 2
x = 67°
The sum 90° + 67° + 23° = 180°
Let's find out.
David needs to score an average of 145 across all four games, so first we do:
145 × 4 = 580
Then we add all the scores he currently has:
139 + 143 + 144 = 426
Then we subtract 426 from 580 to find out how much he needs to score for his fourth:
580 - 426 = 154
David needs to score 154 on his 4th game to have an average score of 145 for all 4 games.
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