$\left \{ {{4x-7y=3} \atop {x-7y=15}} \right. \\\\
 \left \{ {{4x-7y=3} \atop {x=15+7y}} \right. \\\\ substitution\ method\\\\
4*(15+7y)-7y=3\\\\
60+28y-7y=3\\\\
60+21y=3\ \ \ \ | subtract\ \\\\
21y=-57\\\\
y=-\frac{57}{21}=-\frac{19}{7}\\\\
x=15+7*(-\frac{19}{7})=15-19=-4\\\\\ Solution :\ \left \{ {{y=-\frac{19}{7}} \atop {x=-4}} \right.$

5 0

3 years ago

At Priscilla's school, the final grade for her Calculus course is weighted as follows: Tests: 50% Quizzes: 30% Homework: 20% Pri

Sedaia [141]

<h2>Question:</h2>

At Priscilla's school, the final grade for her Calculus course is weighted as follows: Tests: 50% Quizzes: 30% Homework: 20% Priscilla has an average of 87% on her tests, 100% on her quizzes, and 20% on her homework. What is Priscilla's weighted average?

Weighted Average gives weights to each percent of the average as follows:

Weighted Average = Average * weighting percent

Weighted Average = Test Average * Test Weighting + Quiz Average. * Quiz Weighting + Homework Average * Homework Weighting

Weighted Average = 87% * 50% + 100% * 30% + 20% * 20%

Weighted Average = 43.5% + 30% + 4%

Weighted Average = 77.5%

<h2>Answer:</h2>

77.5%

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Thank You!

Answered by: ms115

3 0

2 years ago